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The catalyst for ethylene glycol electrooxidation reaction (EGEOR) is vitally important for direct ethylene glycol fuel cells. Nevertheless, the unsatisfactory EGEOR performance and high-cost of the catalysts still stands as an urgent obstacle that needs to be solved. Herein, we report a fabrication of ceria/nitrogen-doped carbon loaded Pd nanoparticles (Pd–CeO 2 /NC) as an electrocatalyst for EGEOR. During the catalyst synthesis, the renewable and abundant bioresource lignin serves as a precursor to prepare the nitrogen-doped porous carbon (NC), which can save the cost of the carbon support. Ulteriorly, the CeO 2 -doped NC acts as the support to immobilize the Pd nanoparticles by a water-phase reduction approach. Consequently, due to the synergistic effects between the highly-dispersed Pd nanoparticles, CeO 2 and NC, the resultant catalyst affords a current density of 46.39 mA cm−2, which is 2.86 times higher than that of commercial Pd/C (16.22 mA cm−2). Moreover, the developed catalyst also presents better EGEOR stability. This work not only develops a highly active EGEOR catalyst, but also provides an effective method for efficiently utilizing renewable biomass resources. • Multi-component Pd–CeO 2 /NC nanocomposites have been synthesized. • The renewable bioresource lignin serves as precursor for preparing carbon support. • The as-prepared catalysts present superior electrocatalytic performance. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs), an emerging nanomaterial, have shown significant promise in the materials science. This study aims to electrochemical deposited reduce carbon dots (RCDs) and pectin (PC) scaffold on the pencil graphite electrode (PGE), resulting a multifunctional electrocatalyst support (PC/RCDs/PGE) for electroloading of the nickel nanoparticles (NiNPs) to creates the NiNPs/PC/RCDs/PGE for electrooxidation of ethanol. Comprehensive surface and structural analysis and chemical identification methods were utilized for characterization of the modified electrode. Evaluation as an electrocatalyst for ethanol oxidation in 0.1 M NaOH, demonstrated that the NiNPs/PC/RCDs/PGE shows high electrocatalytic activity (Jp = 112 mA cm−2), outperforming several comparisons modified electrodes, RCDs/PGE, NiNPs/RCDs/PGE, NiNPs/PC/PGE, and NiNPs/PGE. These findings suggest that the RCDs and PC scaffold enhances the electrocatalytic activity of the NiNPs via the increasing the surface area of electrodeposited NiNPs and synergistic effect of nanocomposite components, indicating potential for significant advancements in non-platinum ethanol oxidation electrocatalysts. [Display omitted] • The RCDs were electrodeposited at PGE by electroreduction of the synthesized CDs. •The PC was electrodeposited on/in RCDs/PGE for first time to produce PC/RCDs/PGE. •The NiNPs/PC/RCDs/PGE was prepared by electroloading of NiNPs on/in PC/RCDs/PGE. •The NiNPs/PC/RCDs/PGE was used as a potent electrocatalyst for EOR in 0.1 M NaOH. •The NiNPs/PC/RCDs/PGE displayed high electrocatalytic activity toward EOR in NaOH. [ABSTRACT FROM AUTHOR]

The production of green hydrogen is one of the most demanding and challenging for modern technology. A promising and an effective approach is electrocatalytic anodic urea oxidation reaction to generate hydrogen at cathode under alkaline electrolysis condition. However, it remains crucial for the development of active and stable electrocatalysts for efficient urea oxidation. In this study, we employed the hydrothermal synthesis route for NiFe LDH, NiFe LDO, and Ni(OH) 2. The superior performance of NiFe LDH compared to other catalysts is observed due to easy charge transfer facilitated by Fe ions. Moreover, Fe incorporation prevents surface poisoning of the electrocatalyst, resulting in increased activity and stability for electrocatalytic urea oxidation reaction. The influence of different electrolyte environments on the performance of urea-based electrolyzers for sustainable hydrogen production and management of urea-rich wastewater has been measured for the first time by varying oxygen saturation and nitrogen purging conditions. In cyclic voltammetry studies, O 2 -saturated and purging conditions outperformed N 2 gas saturation or purging. The findings of this study provide valuable insight into the design of practical and environmentally friendly urea electrooxidation systems. Continuous O 2 purging enhances urea electrooxidation effectively and efficiently with NiFe LDH. [Display omitted] • An investigation of the effect of electrolyte environment for efficient urea electrooxidation. • NiFe LDH offers greater electrocatalytic activity for UOR compared to NiFe LDO and Ni(OH) 2. • Oxidation reaction switches due to NaOH concentration and promotes enhanced urea electrooxidation. • Urea electrooxidation is enhanced by oxygen saturation and purging by releasing more OH- ions. • Nyquist and Bode plots analysis at wide potential range and varying electrolyte conditions. [ABSTRACT FROM AUTHOR]

The selective electrooxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is of great significance in replacing terephthalic acid for the production of high-performance polymeric materials. This necessitates the development of advanced electrocatalysts. Ni-based nanomaterials, known for their unique electronic structure and high intrinsic activity, show great promise for the selective electrooxidation of HMF to FDCA. To provide guidance for the further development of advanced HMF electrocatalysts, we present a comprehensive review of recent progress in this field, focusing on HMFOR mechanisms, effective engineering strategies (e.g., morphology design, defect engineering, interface engineering, and strain engineering) for improving electrocatalytic performance, and representative Ni-based catalysts used for HMFOR. Finally, we offer a conclusion and highlight the challenging issues that need to be addressed, providing researchers with direction for future endeavors. • A review on the oxidation of HMF into FDCA catalyzed by Ni-based materials is summarized. • The mechanisms of HMF electrooxidation are described thoroughly. • Strategies for optimizing the catalytic performance of Ni-based materials for HMFOR are mentioned. • Recent progresses, challenges, and perspectives are highlighted. [ABSTRACT FROM AUTHOR]

Methanol oxidation reaction (MOR) is used to provide electrical energy via direct methanol fuel cell (DMFC), which requires a practical design of electrocatalysts to accelerate the sluggish MOR. In this study, we successfully fabricated the carbon black nanoparticles/graphite ceramic electrode (CBNPs/GCE) supported metal-organic frameworks (MOFs) and decorated with nickel nanoparticles (NiNPs) as a new type nanocomposite modified electrode (NiNPs/MOFs/CBNPs/GCE) via a chemical and an electrochemical process, respectively. The surface morphology and structure of the synthesized nanocomposite materials and modified electrodes were characterized using field emission scanning electron microscopy, energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analysis. Then, the NiNPs/MOFs/CBNPs/GCE was used as a non-platinum electrocatalyst for electrocatalytic oxidation of methanol in alkaline media. The obtained results show the efficient electrocatalytic activity of the NiNPs/MOFs/CBNPs/GCE toward the MOR with high anodic peak current density (J pa = 34.8 mA cm−2) compared with the other prepared electrocatalysts; MOFs/CCE, NiNPs/CCE, MOFs/CBNPs/GCE, NiNPs/CBNPs/GCE, and NiNPs/MOFs/CCE, due to the synergistic effect of nanocomposite components; NiNPs, MOFs and CBNPs. The prepared electrocatalyst; NiNPs/MOFs/CBNPs/GCE, not only shows a high electrochemically active surface area (ECSA = 2.15 cm2) but also has long-term durability in MOR. In general, it can be said the NiNPs/MOFs/CBNPs/GCE is a promising candidate for application in DMFC. The preparation of the new type nanocomposite, construction processes of the NiNPs/MOFs/CBNPs/GCE and its application in MOR. [Display omitted] • The present MOFs was synthesized by a simple and rapid solvothermal method. • The dropped MOFs at the surface of CBNPs/GCE was decorated with NiNPs to fabricate the NiNPs/MOFs/CBNPs/GCE. • The synthesized nanocomposite and modified electrodes were characterized by the appropriated methods. • The NiNPs/MOFs/CBNPs/GCE was used as a potent electrocatalyst for MOR in alkaline media. • The NiNPs/MOFs/CBNPs/GCE displayed enhanced electrocatalytic activity toward MOR with high stability and durability. [ABSTRACT FROM AUTHOR]

A hybrid electrolytic water system was constructed including the anodic electro-oxidation treatment of the leachate from a waste incineration plant as well as the coupled cathodic electrolysis for hydrogen production. Four types of electrolyzers were designed with different flow channels and investigated the effect of different electrolysis parameters on the coupled reactions. The results indicate that the pin-type electrolyzer is superior to the other three electrolyzers in term of the degradation performance and energy consumption. At high current density of 4000 A/m2 and the flow rate of 100 ml/min, the pin-type electrolyzer shows the lowest potential of 6.09 V, the COD removal rate of 98.17% for the leachate and the energy consumption of 200.14 W h. The mass transfer mechanism was further explored under different flow channels and current densities, illustrating that the excellent performance of the pin-type electrolyzer is due to its largest mass transfer area and the most uniform inside flow field distribution. The apparent COD degradation kinetic behaviors were studied, indicating that the maximum degradation rate was 0.033 min-1 at the electric density of 4000A/m2. Such electrocatalytic oxidation of waste leachate coupled with hydrogen production would provide a promising route to construct new hybrid electrolytic water systems. [Display omitted] • Electrooxidation of leachate is successfully coupled with hydrogen production. • The coupled electrolytic water system operates well at 4000-5000A/m2. • COD removal rate is 98.17% in Pin-type electrolyzer at 4000A/m2 and 2h • Flow patterns in different electrolyzer channels are studied using PIV. • The apparent kinetics of leachate electrooxidation degradation were studied. [ABSTRACT FROM AUTHOR]

PdM/RGN (M = Co, Cu) self-supporting composite electrodes were synthesized via a simple two-step spontaneous reduction process using Ni foam as the substrate and reduced graphene oxide as support layer. The composites were characterized using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy were performed to study the electrocatalytic activities of the prepared electrodes for methanol and ethanol oxidation. The performances of PdM/RGN for methanol and ethanol oxidation increased and then decreased as the atomic ratio of Pd to M (Co, Cu) increased. The Pd 6 Co 1 /RGN and Pd 6 Cu 1 /RGN electrodes exhibited markedly superior catalytic activity and long-term stability. The peak current densities of Pd 6 Cu 1 /RGN and Pd 6 Co 1 /RGN electrodes reached 0.36 and 0.29 A/cm2 for methanol electrooxidation and which reached 0.8 and 0.5 A/cm2 for the ethanol electrooxidation, respectively. This excellent performance is owing to the three-dimensional structure of nickel foam, the improving specific surface area and the synergistic effect between Pd and M. [Display omitted] • The electrode manufacture process is facile, green, low energy consumption and binder-free. • Three-dimensional graphene substrate support resulted in excellent stability of PdM/RGN (Co,Cu). • Good synergy in PdM nanoparticles promotes electron transport and increases surface area. • The PdM/RGN (Co,Cu)electrode exhibitshigh catalytic performance for MOR and EOR. [ABSTRACT FROM AUTHOR]

The biomass electrochemical oxidation has attracted worldwide attention owning to its carbon-neutral and sustainable nature. Here, different morphologies of CoCu-carbonate hydroxides (CH) electrodes are prepared through one-step hydrothermal method for 5-hydroxymethylfurfural electrocatalytic oxidation (HMF-ECO) to high-valued 2,5-furandicarboxylic acid (FDCA) for the first time. The results illustrate that Cu can regulate CoCu–CH morphologies from 1D nanorods to 2D ultra-thin nanosheets besides modulating the catalytic compositions. The optimal Co 1 Cu 1 –CH exhibits hybrid nanostructures containing the 1D nanorods and 2D ultra-thin nanosheets, which has the largest ECSA and specific surface area, as well as the smallest Tafel slope and impedance. The oxidation potential of HMF-ECO is 1.42 V vs RHE with the conversion of HMF 99.57%, the selectivity for FDCA 99.91%, and the FE 98.88%. In addition, Cu can promote the conversion of Co2+ to the favorable Co3+ for HMF-ECO on the catalyst surface. Density functional theory calculation indicates that Cu can improve charges transfer to HMF and lower its adsorption energy. In situ Raman spectra tests indicate that cobalt species is the active site for HMF-ECO. Furthermore, at 1.42 V vs RHE, the coupling of HMF-ECO and hydrogen evolution reaction shows that the cathodic hydrogen evolution rate is 92.33 L h−1 m−2, which is 3.69 times more than water splitting. This work provides a special structures material to process intensification of HMF electrooxidation coupling hydrogen production. [Display omitted] • Cu can regulate Co–CH forming different morphologies and nanostructures. • CoCu–CH catalysts exhibit highly efficient for HMF-ECO to FDCA. • HMF-ECO boosts H 2 evolution rate at 92.33 L h−1 m−2, 3.69 times than water splitting. • DFT illustrates Cu can improve charge transfer to HMF and lower its adsorption energy. • In situ Raman shows the cobalt species is the active site. [ABSTRACT FROM AUTHOR]

In this study, activated carbon is produced from defatted hazelnut bagasse at different activation conditions. The catalytic activities of activated carbons are evaluated for NaBH 4 methanolysis and electrooxidation. These materials are characterized by N 2 adsorption-desorption, FTIR, SEM-EDS and XPS and results show that these materials are prepared successfully. N 2 adsorption-desorption results reveal that activated carbon (FH3-500) has the highest BET surface area as 548 m2/g, total pore volume as 0.367 cm3/g and micropore volume as 0.205 cm3/g. On the orher hand, as a result of hydrogen production studies, FH3-500 activated carbon catalyst has the highest initial hydrogen production rate compared to other materials. At 50 °C, this metal-free activated carbon catalyst has a high initial hydrogen production rate of 13591.20 mL/min.g cat , which is higher than literature values. Sodium borohydride electrooxidation measurements reveal that FH2-500 also has the highest electrocatalytic activity and stability. Hazelnut pulp-based activated carbons are firstly used as a metal-free catalyst in the methanolysis and electrooxidation of sodium borohydride, and its catalytic activity is good as a metal-free catalyst. The results show that the hazelnut pulp-based activated carbon catalyst is promising as a metal-free catalyst for the methanolysis and electrooxidation of sodium borohydride. • Hazelnutt bagasse based activated carbon (HBAC) is prepared and characterized succesfully. • HBAC catalyst has good performance with 13591.20 mL/min g cat value for NaBH4 methanolysis. • HBAC has good perfomace for NABH4 electrooxidation with 1.8 mA/cm2 current density value. [ABSTRACT FROM AUTHOR]

Fuel cells are a very good candidate to provide energy conversion with green technology. Glucose is used as a fuel in fuel cells since it is easily available and has a high energy density. Herein, hydroxyapatite (HAp) was synthesized by precipitation method, and the sodium borohydride (NaBH 4) reduction method was used to fabricate HAp supported PdIn (PdIn/HAp) alloy anode catalysts at varying atomic molar ratios for glucose electrooxidation. Structural, crystallographic, and morphological properties of the PdIn/HAps were determined with X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) analysis, transmission electron microscopy (TEM), and inductively coupled plasma mass spectrometry (ICP-MS). Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and chronoamperometry (CA) were employed for the electrocatalytic activity and stability of PdIn/Haps toward glucose electrooxidation. The results show that HAp has a boosting effect for PdIn alloy towards glucose electrooxidation. Pd 80 In 20 /HAp showed 2.6 times higher electrocatalytic activity than Pd/HAp, and it is the most active and stable catalyst in this study with a specific activity of 5.64 mA/cm2. [Display omitted] • PdIn/HAp catalysts with varying atomic molar ratios were synthesized by the NaBH 4 reduction method. • Pd 80 In 20 /HAp exhibited excellent electrocatalytic activity for glucose electrooxidation. • Pd 80 In 20 /HAp showed long-term stability as a DGFC anode catalyst. [ABSTRACT FROM AUTHOR]

Herein, carbon nanotube (CNT)-supported Ga@PdAgCo catalysts were synthesized by sodium borohydride (SBH) sequential reduction method. These catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-mass spectrometry (ICP-MS). Characterization results revealed that these catalysts were succesfully preared at desired loading and atomic ratios. From the XRD pattern, the crystallite size of 0.5% Ga@PdAgCo(80:10:10)/CNT catalysts was found as 6.95 nm by utilizing the Scherrer equation. From TEM measurements, the average particle sizes of Pd/CNT, PdAgCo(80:10:10)/CNT, and 0.5% Ga@PdAgCo(80:10:10)/CNT catalysts were found to be 54 nm, 25 nm, and 7 nm, respectively. It is clear that particle sizes obtained from TEM and XRD were close to eachother. Electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and cyclic voltammetry (CV) measurements were realized to examine the formic acid and ethylene glycol electrooxidation performances of catalysts. 0.5% Ga@PdAgCo(80:10:10/CNT) and 7% Ga@PdAgCo(80:10:10/CNT) catalysts had the best specific activity and mass activity as 3.37 mA/cm2 (297.61 mA/mg Pd) and 4.95 mA/cm2 (462.59 mA/mg Pd) for ethylene glycol and formic acid electrooxidation, respectively. In addition, EIS results showed that Ga@PdAgCo(80:10:10/CNT) catalyst had a faster electron transfer rate via low charge transfer resistance. As a result, 0.5% Ga@PdAgCo(80:10:10/CNT) catalyst is a promising new anode catalyst for direct ethylene glycol fuel cells. • CNT supported Ga@PdAgCo catalysts were synthesized by sequential NaBH 4 reduction method. • Ga@PdAgCo catalysts were examined for formic acid and ethylene glycol electrooxidation. • 0.5% Ga@PdAgCo(80-10-10/CNT) and 7% Ga@PdAgCo(80-10-10/CNT) provided the best specific activity. • 0.5% Ga@PdAgCo(80-10-10/CNT) catalyst is a promising new anode catalyst for direct ethylene glycol fuel cells. [ABSTRACT FROM AUTHOR]

In recent years, transition metal catalysts due to their low price, excellent conductivity and high activity have been extensively studied in OER. It is worth noting that Co3+ plays a vital role in the process of oxygen evolution catalysis, because Co3+ ions are considered to be active sites. The development of catalysts with high Co3+ content has important application prospects for improving water oxidation efficiency. This paper uses a simple ligand-assisted synthesis method to promote the transformation of two-dimensional layered double hydroxides (LDHs) into two-dimensional metal organic frameworks (MOFs). MOF-OH/NF are quickly and easily prepared by electrooxidation, which exhibit superior OER properties, with a low overpotential of 260 mV and 420 mV for the oxygen evolution reaction (OER) at 100 mA cm−2 and 1000 mA cm−2. Moreover, the MOF-OH/NF has good stability in 1.0 M KOH electrolyte solution. This study provides a new idea for the design and synthesis of novel composite electrocatalysts. • The NiCo x O y /NF is synthesized by a facile electrooxidation method. • High content Co3+ species exist on the surface of the NiCo x O y /NF. • Providing optimized η 100 and η 1000 of 260 mV and 420 mV for OER, respectively. • NiCo x O y /NF exhibits eminent stability and holds steady even during 100 h OER. [ABSTRACT FROM AUTHOR]

The use of fossil energy has caused a serious burden on the environment, so it is urgent to find new and developable energy sources. H 2 O 2 as a new type of clean fuel for fuel cell has received widespread attention. In this paper, a novel graphite modified paper based cobalt-cobalt oxalate-nickel (FG@Co–CoC 2 O 4 –Ni) electrode is fabricated by the simple "pencil depicting-electrodeposition-oxalic acid etching-electrodeposition" process for the electrooxidation of H 2 O 2 in alkaline environment. The as-prepared FG@Co–CoC 2 O 4 –Ni electrode owns a novel and special three-dimensional (3D) porous structure, which can greatly increase the diffusion of reactants (NaOH and H 2 O 2) during the electrochemical reaction process and lead a high catalytic activity for the electrooxidation of H 2 O 2. More importantly, three main nanomaterial (Co, CoC 2 O 4 and Ni) and some new generated substances during the CV test in NaOH solution (e.g. Ni(OH) 2 , NiOOH, Co(OH) 2 , CoOOH, Co 3 O 4 and Co 2 O 3 etc.) are on the surface of paper, which will enhance the electrocatalytic activity of the FG@Co–CoC 2 O 4 –Ni electrode to a great extent due to their synergistic effect. When the reaction solution contains 1.0 mol dm−3 NaOH and 0.2 mol dm−3 H 2 O 2 , the FG@Co–CoC 2 O 4 –Ni electrode exhibits a much higher oxidation current density (270.6 mA cm−2) than the FG, FG@Co, FG@Ni, FG@Co–Ni and FG@Co–CoC 2 O 4 electrodes. Besides, the whole preparation process for the FG@Co–CoC 2 O 4 –Ni electrode doesn't use any organic binder, ensuring the electrode owns good conductivity and stability for the electrochemical reaction. At last, the electrocatalytic mechanism for the electrooxidation of H 2 O 2 is discussed. The Ni compounds and Co compounds are believed as the main catalytic substances, and the metallic Co core provides a fast route for the transfer of electrons. The super catalytic activity makes the prepared electrode in this study to be a promising material for the electrooxidation of H 2 O 2 and the novel design idea gives some guidance for the fabrication of electrode materials in the field of fuel cell. [Display omitted] • The environmentally and inexpensive filter paper is used as electrode support. • The 3D porous electrode structure can improve the catalytic performance. • The synergistic effect among complex substances can enhance the performance. • The as-prepared electrode has high catalytic activity at low H 2 O 2 concentration. • The as-prepared electrode has a fast electron transfer path. [ABSTRACT FROM AUTHOR]

In order to find out electrocatalysts based on non-precious metals, Ni–Co/GO-TiO 2 composite with different amounts of nickel and cobalt is prepared and the impacts of TiO 2 nanoparticles on GO support are highlighted. Composition, morphology and textural features of the synthesized materials are characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, N 2 adsorption-desorption isotherms and field emission scanning electron microscopy equipped with energy-dispersive X-ray analysis. The electrochemical activity of the prepared catalysts toward methanol and ethanol electrooxidation in alkaline media is investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry. Results confirmed that adding TiO 2 nanoparticles to graphene oxide can increase the surface area, porosity and electrochemically active surface area of the support material. The composition with the equal amount of nickel and cobalt precursors exhibited the highest current density for methanol and ethanol electrooxiation equal to 121.07 and 145.28 mA/cm2, respectively. Stability test results demonstrated that this sample maintains 94.1% and 87.5% of initial current density after 7200 s for the electrooxidation of ethanol and methanol in 1.0 M KOH, respectively. All results confirm the synergic effect of Ni and Co for the alcohols oxidation in alkaline media and equal amount of Ni and Co leads to the best catalytic performance with the highest current density, lowest impedance and maximum stability. [Display omitted] • GO-TiO 2 was synthesized using a reflux method as support for fuel cell's catalyst. • Ni-Co was deposited on GO-TiO 2 in chemical reduction method. • The electrochemical properties of samples with various amounts of Ni-Co investigated. • Ni-Co/GO-TiO 2 used as electrocatalyst for the alcohol electrooxidation. • The results showed that Ni-Co/GO-TiO 2 has high current density and low impedance. [ABSTRACT FROM AUTHOR]

Electrooxidation (EO) is a promising wastewater treatment technology that is plagued with high energy consumption. This study simulates the energy recovery potential from EO by process integration with recuperated micro gas turbine (RMGT). Gainful utilization of hydrogen produced at cathode is key to it. Percent recoverable energy (PRE) from EO would be strongly influenced by the cathodic current efficiency (CCE) and interelectrode potential (IP) and was likely to vary from a high of 46% to a low of 14%. Simulations suggested that process integration with RMGT could potentially recover 72.4% of this energy – 30.7% as electricity and 41.7% as thermal energy in the form of hot water at 353 K. This translated to 6.3%–9.7% electricity saved in EO besides recovered thermal energy. Energy dynamics was found to be highly sensitive to recuperator performance of the RMGT. Better recuperator performance made energy recovery through process integration more electricity driven at the cost of recovered heat and total energy recovery. • 14–46% input energy in electrooxidation recoverable as hydrogen. • Process integration with recuperated Micro Gas Turbine can recover 72.4% energy. • 30.7% energy can be recovered as electricity and 41.7% as hot water. • Overall 10% electricity saving in electrooxidation possible. • ACE, IP, and recuperator performance are critical. [ABSTRACT FROM AUTHOR]

Thiophene based heterocyclic compounds plays important roles in organic chemistry due to their unexpected properties. Herein, novel benzothiophene derivatives (6A-F) are synthesized via Sonogashira coupling, iodocyclization reaction, Suzuki-Miyaura coupling and condensation reactions. After characterization of design molecules, their glucose electrooxidation activities are investigated. Electrochemical measurements are performed by cyclic voltammetry, chrono amperometry, and electrochemical impedance spectroscopy in 1 M KOH +0.5 M C 6 H 12 O 6 solution. This results show that the highest performance organic-based catalysts is obtained as 0.729 mA/cm2 (3.345 mA/mg) for the 2-(4-(2-pentylbenzo b thiophen-3-yl)benzylidene)malononitrile (6B). Furthermore, 6B catalyst is shown long term stability, the best current density value (1.151 mA cm−2), and the best transfer resistance load between organic-based catalysts. As a result, it is clear that these benzothiophene derivatives are promising organic based catalyst, an alternative to the expensive Pd and Pt based metal catalyst, for direct glucose fuel cell anode. Image 1 • Benzothiophenes are developed for glucose electrooxidation. • 2-(4-(2-pentylbenzo[b]thiophen-3-yl)benzylidene)malononitrile has superior activity. • 2-(4-(2-pentylbenzo[b]thiophen-3-yl)benzylidene)malononitrile has good stability. • Benzothiophene derivatives are promising anode catalysts for glucose fuel cells. [ABSTRACT FROM AUTHOR]

The solution combustion synthesis was used for preparation of porous CeO 2 with two different fuels; glucose and citric acid, for combustion. The samples of porous CeO 2 are labeled as PCO Glu and PCO Cit. The surface area of PCO Cit and PCO Glu were estimated as 44.50 ± 0.12, and 47.72 ± 0.16 m2 g−1, respectively. The cavities acidity, OH groups on surface, and its bond strength to the active cerium sites are compared by measuring the p H of zero charges; that it was 11.95 ± 0.02, and 11.90 ± 0.03 for PCO Cit and PCO Glu , respectively. The nanosized palladium (NPd) was loaded on PCO Glu and PCO Cit via wetness incorporation. As-prepared nano-microstructure electrocatalysts are utilized in the electrooxidation of C1 compounds, including methanol, formaldehyde, and formic acid. The NPd-PCO Glu presents higher electrocatalytic activity, stability and CO-tolerance ability for the electrooxidation of C1 compounds as compared to the NPd-PCO Cit and NPd as non-supported palladium; So that, the performance of the modified electrodes increase in the order of NPd < NPd-PCO Cit < NPd-PCO Glu. The PCO with porous structural network affected on the electrochemical surface area, dispersion, and durability of NPd. It is effective the capability of removing the poisoning species of the electrooxidation of C1 compounds on NPd through the lattice oxygen, and the activation of an oxidation−reduction cycle between the high and low chemical valences of cerium, leading to improve the electrocatalytic efficiency of NPd. Lastly, the conversion of methanol to formaldehyde, and then to formic acid during electrooxidation is confirmed by using cyclic voltammetry. • Fabrication and characterization of porous CeO 2. • Incorporation of porous CeO 2 as novel support for nanosized palladium. • Study of electrooxidation efficiency of C1 compounds. • Evaluation of the electrooxidation mechanism of C1 compounds. [ABSTRACT FROM AUTHOR]

Simultaneous carbon and nitrogen monoxide oxidations were studied on different platinum surfaces to envisage the kinetics and mechanism of oxidations in acid media. Nanosized platinum specimens were prepared by an electrochemical method without chemical capping agents and platinum ion precursors. Crystalline oriented particles were obtained from a platinum surface by applying symmetric or asymmetric potential programs in concentrated sulfuric acid followed by cathodizations at very large negative potentials. Nitrogen monoxide arising from nitrite solutions showed synergetic oxidation profiles when first scanning the potential towards cathodic values in solutions containing carbon monoxide. Nitrite oxidative desorption to nitrate arose as a mass controlled process, whereas carbon monoxide oxidation to carbon dioxide occurred firstly from its adsorbate and then associated with carbon monoxide bulk solution. Tafel lines were derived including the potential dependence of surface coverages by oxygen containing adsorbates together with those by carbon and nitrogen monoxides. No changes for nitrogen oxide oxidation Tafel slopes were detected either in the presence or the absence of carbon monoxide (ca. 0.120 Vdec−1) above 1 V, whereas carbon monoxide oxidation varies the slope from 0.040 to ca. 0.060 Vdec−1 when nitrogen monoxide adsorbates were formed. Electrochemical performance of CO, NO and CO + NO on Pt nanospheres. Image 1 • (111), (110), (100) platinum nanocrystals were prepared by square wave programs. • Synergetic effects between carbon and nitrogen monoxide oxidation were found. • Changes in Tafel slopes were assigned to potential dependent coverages. [ABSTRACT FROM AUTHOR]

In this work, we report a facile method of synthesis of carbon supported Pd, PdRu, and PdNi nanoparticles, and a comparative study of their catalytic behavior for the electrooxidation of ethanol in alkaline media. The addition of metals such as Ru or Ni increases the oxophilicity of the Pd surface, as observed from the shifting of the Pd oxide reduction peaks. As a consequence, the onset potential for the electrooxidation of ethanol shifts to less positive values on the bimetallic catalysts. The nature and evolution of the species formed during the electrooxidation of ethanol over the catalysts under study has been monitored using in situ infrared spectroscopy. In order to assess properly the evolution of the species formed during the electrooxidation of ethanol, infrared spectra have been recorded in both H 2 O and D 2 O electrolytes. The results presented in this work demonstrate that the scission of the C–C bond of ethanol takes place at the surface of Pd/C and PdM/C (M = Ni and Ru) at potentials as low as 30 mV. However, at potentials above E ≥ 400 mV, acetates are the main species formed during the electrooxidation of ethanol. • Pd(M)/C (M = Ru and Ni) catalysts are very active for the EOR in alkaline electrolyte. • In situ IRRAS during EOR demonstrate C–C scission at low potentials. • Acetyls are not detected by IRRAS during the EOR. • The C2 pathway (mainly acetates) is the preferred pathway at high potentials. [ABSTRACT FROM AUTHOR]

Improved performance and reduced costs are crucial to develop catalysts for direct formic acid fuel cells. In this study, PdBi alloy nanoparticles were synthesized using a facile seed-mediated growth method. The as-synthesized Pd 1 Bi 1 alloy nanoparticles exhibited a large electrochemical surface area (46.3 m2 g−1) and a high mass activity (1.44 A mg−1), which was 1.19- and 4.8-fold higher than that of commercial Pd/C catalysts, respectively. The PdBi alloy nanoparticle is a promising catalyst for direct formic acid fuel cells. • PdBi nanocatalysts are prepared by a very facile seed-mediated growth method. • The Pd 1 Bi 1 catalysts show the largest mass activity, which are 4.8 times higher than the commercial Pd/C catalysts. • The Pd 1 Bi 1 catalysts display the best stabilities, which are 4.6- fold higher than the commercial Pd/C catalysts. [ABSTRACT FROM AUTHOR]

Abstract Aliphatic alcohol mainly, ethanol, methanol and their mixture were subjected to electrooxidation study using cyclic voltammetry (CV) technique in a three electrodes half cell assembly (PGSTAT204, Autolab Netherlands). A single cell set up of direct alcohol alkaline fuel cell (DAAFC) was fabricated using laboratory synthesized alkaline membrane to validate the CV results. The DAAFC conditions were kept similar as that of CV experiments. The anode and cathode electrocatalysts were Pt-Ru (30%:15% by wt.)/Carbon black (C) (Alfa Aesar, USA) and Pt (40% by wt.)/High Surface Area Carbon (C HSA) (Alfa Aesar, USA) respectively. The CV and single cell experiments were performed at a temperature of 30 °C. The anode electrocatalyst was in the range of 0.5 mg/cm2 to 1.5 mg/cm2 for half cell CV analysis. The cell voltage and current density data were recorded for different concentrations of fuel (ethanol or methanol) and their mixture mixed with different concentration of KOH as electrolyte. The optimum electrocatalyst loading in half cell study was found to be 1 mg/cm2 of Pt-Ru/C irrespective of fuel used. The single cell was tested using optimum anode loading of 1 mg/cm2 of Pt-Ru/C which was found in CV experiment. Cathode loading was kept similar, in the order of 1 mg/cm2 Pt/C HSA. In single cell experiment, the maximum open circuit voltage (OCV) of 0.75 V and power density of 3.57 mW/cm2 at a current density of 17.76 mA/cm2 were obtained for the fuel of 2 M ethanol mixed with 1 M KOH. Whereas, maximum OCV of 0.62 V and power density of 7.10 mW/cm2 at a current density of 23.53 mA/cm2 were obtained for the fuel of 3 M methanol mixed with 6 M KOH. The mixture of methanol and ethanol (1:3) mixed with 0.5 M KOH produced the maximum OCV of 0.66 V and power density of 1.98 mW/cm2 at a current density of 11.54 mA/cm2. Highlights • Ethanol shows promising result in a mixture of methanol and ethanol. • Low cost PVA based alkaline membrane was successfully synthesized in laboratory. • The ionic conductivity of the PVA based alkaline membrane was excellent. • PVA based alkaline membrane is suitable for low temperature application. [ABSTRACT FROM AUTHOR]

Abstract Shape-controlled synthesis of well-defined nanostructures offers a great opportunity to promote electrocatalytic performances while reducing the mass loading of noble metals. Herein, we show how morphology can effectively affect the electrocatalytic properties of nanocrystals for alcohol electrooxidation reaction, a key barrier to the application of fuel cells. We report the synthesis of a new generation of alloyed PtSn concave nanocubes (CNCs) through a facile one-pot wet-chemical method. Owing to strong synergistic effect between Pt and Sn, modified electronic structure, as well as high surface areas, the as-obtained alloyed PtSn CNCs can display outstanding electrocatalytic performances for liquid fuel electrooxidation. Impressively, the optimized Pt 4 Sn 1 concave nanocubes (CNCs) can achieve a factor of 5.1 enhancements in mass activity and a factor of 5.9 enhancements in specific activity towards ethylene glycol oxidation (EGOR) in comparison with commercial Pt/C catalysts. Moreover, 4.6 and 5.3-fold enhancements in mass and specific activity were also acquired for glycerol oxidation reaction (GOR) compared to those of the commercial Pt/C, holding great promise for future application in fuel cells. Graphical abstract Image 1 Highlights • A unique class of concave PtSn nanocubes has been designed. • Such concave PtSn nanocubes can expose more surface active areas. • The synergistic effect contributes to the enhancement of catalytic performances. • Such concave PtSn nanocubes show high performance for EGOR and GOR. [ABSTRACT FROM AUTHOR]

Abstract The decoration of Pt 1 Ni 3 nanoparticles supported on carbon black with Au adatoms and the electrocatalytic activity of the Au-decorated Pt 1 Ni 3 /C (Au/Pt 1 Ni 3 /C) for the oxidation of ethylene glycol (EG) in alkaline solution have been investigated. The decoration of Pt 1 Ni 3 /C with Au is performed by potentiostatically depositing a small amount of Au on Pt 1 Ni 3 /C, and the Au/Pt 1 Ni 3 /C catalysts with Au/Pt atomic ratios of ca. 0.02:1 and 0.08:1 are obtained. Physical and electrochemical characterizations reveal that a small part of the surface of Pt 1 Ni 3 nanoparticles is covered by Au adatoms. In EG oxidation, the performances of Pt 1 Ni 3 /C before and after the Au decoration are quite different. Au/Pt 1 Ni 3 /C shows remarkably high peak intensity compared to Pt 1 Ni 3 /C, in spite of a decrease in the surface of Pt by Au adatoms. The low Pt content of Pt 1 Ni 3 nanoparticles and the small Au loading also suggest advantages of the Au/Pt 1 Ni 3 /C catalysts in cost. The result of this study reveals a significant enhancing effect of Au adatoms on the activity of Pt 1 Ni 3 /C for EG oxidation. Highlights • Surface of Pt 1 Ni 3 nanoparticles supported on carbon black is decorated with Au. • Au-decorated Pt 1 Ni 3 /C catalysts have Au/Pt atomic ratios of 0.02–0.08:1. • Au-decorated Pt 1 Ni 3 /C shows high catalytic activity for ethylene glycol oxidation. [ABSTRACT FROM AUTHOR]

TiO 2 microflowers assembled by nanosheets are prepared by a one-step solvothermal process. The anatase-TiO 2 (B) dual-phase coexistence or anatase single phase is obtained under different annealing temperatures. Pt nanoparticles supported on the anatase-TiO 2 (B) microflowers are first applied to alcohol electrooxidation. The electrocatalytic performances of Pt/anatase-TiO 2 (B), Pt/anatase and Pt/carbon-black (Pt/C) on graphite substrates are systematically investigated. The Pt/anatase-TiO 2 (B) catalyst exhibits superior electrocatalytic activity and stability compared with that of Pt/anatase and Pt/C catalysts for methanol and ethanol in acidic and alkaline media, which is attributed to the large specific surface area, the porous channels to reduce the liquid sealing effect, the enhanced electronic conductivity by dual-phase coexistence and quick electron transfer from anatase phase to TiO 2 (B). [ABSTRACT FROM AUTHOR]

A microfluidic fuel cell (MFC) is constructed at laboratory for NaBH 4 electrooxidation using varying operating conditions. The temperatures of anode and cathode were varied from 40 °C to 70 °C, and the pressure was maintained at 1 bar. The anode and cathode electrocatalyst used was Pt (40 wt. %)/High Surface Area Carbon (CHSA) with loading in the range of 0.5 mg/cm 2 to 2 mg/cm 2 . The oxidant at cathode was atmospheric oxygen (21 mol % O 2 ). The commercial gas diffusion layer (GDL) was used as substrate at anode and air breathing cathode side. The cell voltage and current density were measured for different fuel (NaBH 4 ) concentration, electrolyte (KOH) concentration, temperature and electrocatalyst loading at anode and cathode, respectively. The maximum open circuit voltage (OCV) of 1.079 V and power density of 24.09 mW/cm 2 at a current density of 54.97 mA/cm 2 were obtained for anode (Pt/C HSA ) and cathode (Pt/C HSA ) loading of 1 mg/cm 2 using 0.1 M NaBH 4 as fuel mixed with 1 M KOH as electrolyte at a temperature of 70 °C. Whereas the maximum power density of 8.47 mW/cm 2 at a current density of 34.04 mA/cm 2 was obtained at the temperature of 40 °C. Although similar cell conditions were used, the cell performance in terms of power density is significantly enhanced (about 65%) due to increase in temperature from 40 °C to 70 °C. These results were validated using cyclic voltammetry at single electrodes under similar conditions to those of the single microfluidic fuel cell. [ABSTRACT FROM AUTHOR]

This work reports the preparation and electrochemical characterization of PtSn/C and PtRh/C modified with a cesium salt of phosphotungstic acid, CsPTA, for use as electrochemical oxidation catalysts in acidic medium. The primary test system is the oxidation of ethylene glycol. Electrode with these modified nanoparticles confined as surface layers are used in studies not only on ethylene glycol but also on all side products of its oxidation in H 2 SO 4 electrolyte. The experimental results reveal that films on carbon electrodes of nanoparticulate PtSn/C and PtRh/C modified with CsPTA enhance the catalytic activity relative to those lacking the CsPTA towards ethylene glycol oxidation. Higher anodic current densities are especially evident at low potentials, particularly below 0.35 V (vs. RHE). Additionally, a preliminary single fuel cell test with the CsPTA-modified PtSn/Vulcan anode shows a better performance than does the PtSn/Vulcan catalyst. [ABSTRACT FROM AUTHOR]

There is significant interest in developing new catalyst supports such as metal carbides to overcome the electrochemical corrosion problem of traditional high surface area carbon. A key challenge is the dispersion and stability of the catalysts on the non-carbon based materials. This paper reports a new approach to functionalize titanium carbide by poly (diallyldimethylammonium chloride) (PDDA), investigated as a new catalyst support for Pd catalyzed electrochemical reaction. Thermal gravimetric analysis confirmed the successful noncovalent functionalization of TiC by PDDA. Pd nanoparticles are deposited in situ on the PDDA-wrapped TiC surface through electrostatic interactions mechanism. According to transmission electron microscopy (TEM) observations, Pd nanoparticles with a mean size of ∼2.9 nm are homogeneously deposited on TiC(P). Among all the samples tested, the Pd/TiC(P) catalysts exhibit the highest resistance to CO poisoning, catalytic activity and stability towards formic acid electrooxidation. This performance was attributed to a strong Pd↔TiC interaction and the formation of oxygenated species on the TiC. [ABSTRACT FROM AUTHOR]

Vulcan XC-72R carbon supported Pd and Pd–Mo alloys of different Pd:Mo atomic ratios were prepared by hydrothermal synthesis method. The bimetallic nanoalloys were characterized by powder X-ray diffractometry and inductively coupled plasma-atomic emission spectroscopy to determine their crystal structures and elemental compositions. Alloy formation of the nanocatalysts was proven by energy dispersive X-ray spectroscopy line profiles using field emission scanning electron microscopy. The performance of as-prepared nanocatalysts was evaluated for the reactions of methanol, ethanol, ethylene glycol and glycerol electrooxidation in alkaline media by cyclic voltammetry, linear sweep voltammetry and chronoamperometric measurements. It was found that bimetallic Pd–Mo/VC catalysts have higher activity due to different electronic structure as compared to the monometallic palladium. Also, the Pd 3 Mo/VC catalyst showed excellent catalytic activity, high durability and stability which indeed propose it to be as a promising electrocatalyst for future direct alcohol fuel cells. [ABSTRACT FROM AUTHOR]

Improving the electrocatalytic activity, durability, and utilization of anode eletrocatalysts are crucial for accelerating commercialization of direct formic acid fuel cells. In this work, the multiwall carbon nanotubes (MWCNTs) supported PtAu alloy nanocrystals (MWCNTs/PtAu) composites are synthesized by a one-pot wet-chemical method using polyethyleneimine as the complexant and surfactant. The physicochemical properties of the as-prepared MWCNTs/PtAu composites are characterized detailedly by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy, etc . These structural investigations display the PtAu alloy nanocrystals are highly dispersed on the surface of the MWCNTs. Cyclic voltammetry and chronoamperometry measurements show the as-prepared MWCNTs/PtAu composites significantly enhance the direct dehydrogenation pathway of the formic acid oxidation reaction, resulting in the improved electocatalytic activity and durability for the formic acid electrooxidation. [ABSTRACT FROM AUTHOR]

In this paper, polypyrrole@multi-walled carbon nanotubes (PPy@MWCNTs) nanocomposite as a catalyst support material is fabricated. Pd nanoflowers (NFs) were deposited on a PPy@MWCNTs modified glassy carbon electrode (GCE) by a facile electrochemical approach. The morphology and composition of the Pd NFs/PPy@MWCNTs are characterized by SEM (scanning electron microscopy) and EDS (energy dispersive spectroscopy), respectively. The catalytic performance of Pd NFs/PPY@MWCNTs catalyst is examined by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy toward methanol oxidation reaction (MOR) in alkaline media. The mass activity of Pd NFs/PPY@MWCNTs (725 mA mg −1 ) is 8.09 times higher than that of the Pd NFs catalyst (89.6 mA mg −1 ). Meanwhile, the ratio of forward current (j f ) to reverse current (j b ) for the polymer supported catalyst is almost 2.6 times higher than that of the Pd NFs. Furthermore, PPY@MWCNTs produces a high activity to electrocatalyst, which might be due to higher electrochemically surface area and electronic conductivity. This strategy provides a promising platform for direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

In this work, a highly active X nanozeolite-supported bimetallic Pt Cu nanoparticles modified carbon paste electrode (Pt Cu-XNZ/CPE) was fabricated for the first time and its electrocatalytic activity toward formaldehyde oxidation was investigated. To do this, the NaX nanozeolite/CPE (NXNZ/CPE) was firstly prepared and then Cu 2+ ions were introduced into nanozeolite structure by ion exchange followed by electrochemical reduction to Cu 0 . Then the partial replacement of Cu species by Pt species was achieved. The characterization of the proposed electrode was performed by energy dispersive X-ray analysis and scanning electron microscopy. Also, the performance of the as-prepared electrode toward formaldehyde electrooxidation was studied by the cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometric techniques. Furthermore, the effects of various parameters including times of ion exchange (t ex ) and replacement (t r ) as well as long-term stability of the prepared electrode were investigated on the formaldehyde oxidation. The obtained results show that the as-prepared Pt Cu-XNZ/CPE indicates good electrocatalytic performance including high current and low overpotential for formaldehyde oxidation. It can be attributed to the presence of zeolites as nanoporous material on the electrode surface which provides the porous structure for bimetallic Pt Cu nanoparticles formation and active sites for formaldehyde oxidation. [ABSTRACT FROM AUTHOR]

In this work, anatase-TiO 2 is investigated as a catalyst support in Pd/TiO 2 –C composite to improve the electrocatalytic properties of Pd for formic acid oxidation reaction (FAOR). Pd/TiO 2 has been synthesized by an impregnation-reduction method and then mixed with Vulcan XC-72R carbon black to obtain Pd/TiO 2 –C composite. Transmission electron microscopy (TEM) images show Pd nanoparticles (ca.3.5 nm in average diameter) in the Pd/TiO 2 –C (1:1) composite catalyst were dispersed on the surface of TiO 2 with a narrow particle size distribution. Electrochemical tests demonstrate Pd/TiO 2 –C (1:1) composite has significantly increased catalytic activity and stability compared with Pd/C for FAOR. The proposed reasons for these observations are the excellent acid corrosion and oxidation resistance of TiO 2 and the synergistic effect of Pd and TiO 2 nanoparticles. The effect of mass ratios of TiO 2 to C on the catalytic performance is also discussed. The best catalytic activity and stability for FAOR is found when the mass ratio of TiO 2 to C is 1:1. It can be interpreted as the synergistic effects and conductivity reach balance at this point. [ABSTRACT FROM AUTHOR]

Different Ni−MnO x /C electrocatalysts were prepared by chemical reduction of nickel ions at MnO x /C, containing various metal oxide weight percentages, as a support. Sodium borohydride was employed as a reducing agent with the aid of microwave irradiation. Electrocatalyst surface morphology, crystalline structure and chemical composition were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX), respectively. Incorporating manganese oxide in Ni−MnO x /C resulted in the formation of smaller and homogeneously distributed nickel nanoparticles. Electrocatalytic activity of Ni−MnO x /C towards methanol oxidation reaction in KOH solution was investigated using cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The oxidation current density was enhanced with increasing MnO x weight percentage to achieve the highest activity at Ni−MnO x /C containing 7.5 wt.% MnO x . The electrocatalyst stability during long-time operation was examined. A lower charge transfer resistance value was measured at Ni−MnO x /C surface when methanol was introduced to the supporting electrolyte. A faster electron transfer rate was observed when MnO x was added in an increased content. [ABSTRACT FROM AUTHOR]

In this study, we report the synthesis of Co@Pt nanoparticles via a fast and simple method and the fabrication of an anodic electrocatalyst, Co@Pt supported on carbon-ceramic substrate, for fuel cell applications. The present synthesis method is very facile and economical which may be suitable for large-scale production of Co@Pt nanoparticles with high activity. The surface morphology, structure and composition of the as-prepared core–shell nanoparticles were characterized by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy. Then, the electrooxidation of ethylene glycol (EG) and glycerol (Gly) was investigated on the Co@Pt nanoparticles supported on carbon-ceramic electrode (Co@Pt/CCE) in 0.5 M H 2 SO 4 solution. Electrocatalytic characteristics were methodically investigated by electrochemical techniques such as cyclic voltammetry and chronoamperometry. The Co@Pt/CCE electrocatalyst demonstrates improved specific activity toward EG and Gly electrooxidation compared to the Pt-alone nanoparticles supported on carbon-ceramic electrode (Pt/CCE) and also shows much high structural stability and tolerance to carbonaceous species poisoning. Therefore, the Co@Pt/CCE can be extended as a promising electrocatalyst for the polyol alcohols electrooxidation reactions in fuel cells. [ABSTRACT FROM AUTHOR]

Bimetallic platinum–bismuth nanoparticles (Pt-BiNPs) were prepared with octa-(3-amino-propyl) silsesquioxane (OA-POSS) for high-performance electrooxidation of formic acid. Characterization of nanoparticles revealed their homogeneous-phase with blackberry-like morphology when the fraction of Bi was no less than 60%. Their electrocatalytic activity was investigated with cyclic voltammetry and chronoamperograms. The prepared bimetallic Pt-BiNPs displayed larger electrochemical surface areas, better electrocatalytic activity and more favourable durability towards electrocatalytic oxidation of formic acid compared with commercial catalysts. The improvement might be ascribed to the role of OA-POSS as the control agent of morphology and the carrier of electrocatalyst with possible corrosive resistance. This study suggested that silsesquioxane might potentially facilitate preparation of homogeneous-phase nanoscaled catalysts for direct formic acid fuel cell in practical applications. [ABSTRACT FROM AUTHOR]

Abstract: Palladium nanowires with a diameter of about 5 nm and length of a few tens of nanometers can be synthesized in the presence of large amount of bromide ions, employing polyvinylpyrrolidone as protective reagent while sodium borohydride as reductant. The obtained Pd nanowires are well dispersed on Vulcan XC-72 carbon. The structure and composition of the as-prepared catalyst are analyzed by transmission electron microscope, X-ray diffraction, energy dispersive X-ray spectrum and inductively coupled plasma optical emission spectrometer. Electrochemical catalytic measurement results prove that the as-prepared catalyst exhibits superior electrocatalytic activity towards ethanol and formic acid electrooxidation. [Copyright &y& Elsevier]

Abstract: Pt modified Pd/C catalysts were synthesized through galvanic replacement method in a one-pot synthetic process, where the replacement reaction was influenced greatly by the presence of the haloids (Cl− or Br−) in the solution. The catalysts with and without Pt modification were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-Ray spectroscopy (EDX) and electrochemical tests. The modified state and atomic ratio of Pt to Pd due to the variation of synthetic conditions were confirmed by the physical characterizations. The variation in structure/surface composition of the Pt–Pd/C catalysts leaded to different reaction mechanism and varied the performance of formic acid electrooxidation, which were confirmed by the electrochemical tests. The Pd/C catalyst modified with Pt in the presence of Cl− possesses satisfactory comprehensive performance, i.e. both stability and activity, for formic acid electrooxidation (FAEO). The results are of significance for designing catalysts for practical application of direct formic acid fuel cell and understanding mechanism of FAEO on noble metals composite structures. [Copyright &y& Elsevier]

Abstract: A new method for the synthesis of the catalyst systems Pt–Mo was suggested. nPt0(H x−2n MoO3)/GC electrodes were prepared by a redox reaction between the hydrogen-containing molybdenum bronzes and potassium tetrachloroplatinate (II) in acid solutions at open circuit potential. The electrodes were characterized by CVA, SEM, X-ray microanalysis, XRD, XPS and ICP-AES. Pt0conglomerates formation with nonuniform distribution over the molybdenum bronzes surface has been revealed. nPt0(H x−2n MoO3)/GC electrodes showed high catalytic activity (not inferior to Pt–Ru-catalyst) in the oxidation of carbon monoxide and methanol as compared with Pt/GC-electrodes. Catalytic effect is apparently achieved by effective oxidation of strongly chemisorbed species (COads, HCOads), which occurs at boundaries platinum – molybdenum oxide. Therefore nPt0(H x−2n MoO3) can be considered as one of perspective catalysts for DMFC. [Copyright &y& Elsevier]

Abstract: A series of novel Pt–Pd/polyfluorenes (PFs) composite catalysts were facilely prepared based on Pt/Pd precursor and PFs with hydroxyl and carboxyl substitution at the C-9 position by electrochemical method and their electrocatalytic performance toward formic acid oxidation were studied. Electrocatalytic experiments demonstrate that the Pt–Pd nanoparticles immobilized on poly(9-fluorenecarboxylic acid) (PFCA)-decorated glassy carbon (GC) electrode (Pt–Pd/PFCA/GC) show larger electrochemical active surface area, higher catalytic activity and stability toward formic acid oxidation than that of other Pt–Pd/PFs/GC, Pt–Pd/GC, as well as the commercial JM 20% Pt/C/GC electrodes, which can be attributed to the small-sized and well-dispersed Pt–Pd nanoparticles on PFCA matrix and the special electronic interaction between the metal nanoparticles and the polymer substrate. Moreover, the electron-withdrawing carboxyl substitution rather than the electron-donating hydroxyl on the polymer main chain is of great benefit to the removal of poison CO as well as the enhancement of catalytic activity of Pt–Pd toward formic acid oxidation. [Copyright &y& Elsevier]

Abstract: Platinum nanoparticles have been successfully assembled on polyaniline functionalized graphite nanoplatelet (GNP) via a noncovalent functionalization strategy. The characterization of obtained nanocomposite was investigated by XRD, TEM, XPS and electrochemical technology. When the moderate amount of polyaniline as a stabilizer, Pt nanoparticles with sizes of approximate 4–5 nm uniformly disperse on GNP surface. In methanol oxidation reaction, the electrocatalytic activity of Pt/PANI-GNP is nearly 2 times higher than that of Pt/GNP catalyst. Through analysis, it is suggested that the electrocatalysis performance of Pt/PANI-GNP may be improved by the following four factors: (1) uniformly distributed nanoparticle; (2) increased of amount of Pt0 and oxygen-containing groups; (3) the existence of N atoms; (4) difference reaction mechanism. [Copyright &y& Elsevier]

Abstract: The dependence of electrooxidation on experimental conditions of organic molecules was investigated to optimize the production of hydrogen from potential wastewater sources using low voltage sources (∼1 V dc). Electrooxidation on platinum, gold, and stainless steel anodes with hydrogen production on the cathode was investigated using several different organic reductants, including: methanol, ethanol, glycerol, isopropanol, propanal, glycerol, glucose, sucrose, citric acid, and propionic acid. The electrolyte pH was varied from 2 to 12 in a 1 M Na2SO4 supporting solution. At 1 V, glycerol, citric acid, ethanol and methanol were found to yield the highest currents at low pH values (pH 2 and 7) on platinum electrode, glucose on gold electrode at pH 12 in 1 M Na2SO4 solution produced the highest total current density at 1 V with measured Faradaic efficiency for 1 M glucose of 70%. The hydrogen energy production efficiency was 86%. Practical limitations of glucose oxidation at optimum experimental conditions are discussed. [Copyright &y& Elsevier]

Abstract: Aucore–Ptshell (Au@Pt) nanoparticles supported on activated carbon (Au@Pt/C) are synthesized by an epitaxial growth method using HCOONa as a reducing agent. Through the characterization of the transmission electron microscope (TEM), high resolution TEM (HRTEM), high angle annular dark-field scanning TEM (HAADF-STEM) and X-ray powder diffraction (XRD), the Pt atoms grow epitaxially on the surface of the Au nanoparticles to form Pt shells with Au fcc structure. According to the results of the X-ray photoelectron spectroscopy (XPS), electrons transfer from Pt to Au. Cyclic voltammetry is employed to investigate the catalytic activities of the Au@Pt/C catalysts for the methanol electrooxidation (MEO) and the CO stripping. The results of the electrochemical measurements indicate that, the Au fcc structure of the Pt shell and the decrease in the electronic effect are propitious to the increases in the catalytic activity for the MEO and the CO tolerance of the Au@Pt/C catalysts. [Copyright &y& Elsevier]

Abstract: The carbon supported Au nanoparticles (Au-NPs) catalyst with a small average size (3.5 nm) and narrow size distribution (2–6 nm) was synthesized by a solution phase-based nanocapsule method. The reactivity of glycerol oxidation on Au/C is much higher than that of methanol and ethylene glycol oxidations in alkaline electrolyte. The anion-exchange membrane-direct glycerol fuel cell (AEM-DGFC) with the Au/C anode catalyst and a Fe-based cathode catalyst shows high performances with both high-purity glycerol and crude glycerol fuel: the open circuit voltages (OCVs) are 0.67 and 0.66 V, and peak power densities are 57.9 and 30.7 mW cm−2 at 80 °C, respectively. Fed with crude glycerol, the Au/C anode catalyst-based AEM-DGFC also demonstrates high performance stability at 80 °C. The product analysis shows that the electrooxidation of glycerol on the Au/C anode catalyst in AEM-DGFCs favors production of deeper-oxidized chemicals: tartronic acid, mesoxalic acid and oxalic acid, which leads to higher fuel cell''s Faradic efficiency. [Copyright &y& Elsevier]

Abstract: Gold nanoparticles supported on activated carbon (Au/C) are prepared by rapid reduction with KBH4, after was partially deposited on the surface of the activated carbon by the reaction of and ammonia. Through the characterization of the transmission electron microscope and X-ray powder diffraction, the mean diameter of the Au nanoparticles (AuNPs) decreases with the increase of the Au loading. The energy dispersive X-ray spectroscopy analysis is carried out for measuring the Au loadings of the Au/C catalysts. The results exhibit the Au/C catalyst with 20 wt% Au has the highest loading efficiency (94.5%). The origin of the catalytic activity of Au/C catalysts for the methanol electrooxidation (MEO) is investigated by the cyclic voltammetry, which indicates that the current densities normalized by the actual Au loading for the MEO increase with a decrease in the mean diameter of AuNPs by a factor of 2.42–3.17. Based on this result, the active sites (corners, edges and step sites) for the MEO are proposed. [Copyright &y& Elsevier]

Abstract: The Pt–Ni nanoparticles supported on carbon–ceramic electrode (CCE) are prepared by an electrodeposited process. The obtained catalyst is characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and cyclic voltammetry. The results show that the Pt–Ni nanoparticles (Flower like), which are uniformly dispersed on carbon–ceramic, are 20–50 nm in diameters. The Pt–Ni/CCE catalyst, which has excellent electrocatalytic activity for formic acid (FA) electrooxidation than a comparative Pt/CCE catalyst, shows great potential as less expensive electrocatalyst for FA electrooxidation. On the other hand, the Pt–Ni/CCE catalyst has satisfactory stability and reproducibility when stored in ambient conditions or continues cycling. These results indicate that the system studied in the present work is the most promising system for use in direct formic acid fuel cells. [Copyright &y& Elsevier]

Abstract: Nanocomposite coatings of Ni–Cr2O3 supported on carbon electrodes have been prepared by electrodeposition technique from nickel Watts bath in presence of Cr2O3 nanoparticles. Their electrochemical catalytic activities have been evaluated towards electrooxidation of ethanol in 1.0 M NaOH solution by using cyclic voltammetry, chronoamperometry and Tafel plots. The performance of the prepared anodes towards electrooxidation of ethanol as a function of co-deposited Cr2O3 content was studied. The catalytic activity of fabricated electrodes increases with increasing the volume fraction percent (Vf%) of Cr2O3 in the deposited film up to 7Vf%. The Ni–Cr2O3/C (7Vf%) electrode displayed significantly enhanced catalytic activity and stability towards electrooxidation of ethanol compared with Ni/C electrode. The kinetic parameters of Ni(OH)2/NiOOH and ethanol oxidation at Ni/C and Ni–Cr2O3/C electrodes have been evaluated. [Copyright &y& Elsevier]

Abstract: Pt is one of the most important electrode materials employed in direct methanol fuel cell, and many efforts have been directed to improving its electrocatalytic performance. In this work, Pt–TiO2 nanocomposites are successfully prepared by a sol–gel method. As revealed by TEM, Pt nanoparticles with an average size of 2.6 nm are well uniformly dispersed on porous TiO2. XRD structural characterization indicates that Pt possesses a face centered cubic crystal structure while TiO2 is in the format of both rutile and anatase phases. The electrochemical performance of as-prepared nanocomposite electrode (Pt–TiO2/ITO) is evaluated by studying the electrocatalytic oxidation of methanol in an alkaline medium with or without UV illumination. Comparative experiments evince that the electrochemical performance of Pt–TiO2/ITO for methanol electrooxidation is markedly improved under UV illumination. Under UV illumination, moreover, the poisoning resistance of Pt–TiO2/ITO for methanol electrooxidation is significantly improved, as supported by the results of time-coursed current measurements. [ABSTRACT FROM AUTHOR]