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Abstract The development of efficient anode nanocatalysts with high performance for direct ethylene glycol fuel cells is highly desirable and still difficult due to the sluggish kinetics at the anode. For that reason, it is necessary to engineer cost-effective Pd-based catalysts with fascinating structure and superior activity. Inspired by this, we shed light on a facile self-template one-pot approach to synthesize sub-24 nm PdAg hollow nanodendrites with tunable compositions. More importantly, owing to the exquisite hollow nanostructure and electronic effect, as well as synergistic role, the as-prepared unique binary PdAg nanocatalysts show outstanding mass activity of 4168.8 mA mg Pd −1 for ethylene glycol oxidation reaction under the alkaline medium, 3.8-fold enhancements than that of commercial Pd/C catalysts. Remarkably, based on this facile synthesis method and superior electrocatalytic performance of as-prepared catalysts, we believe that our efforts will open a new way to promote the commercialization of fuel cells to some extent. Graphical abstract Image 1 Highlights • A simple self-template tactic was used to prepare the PdAg hollow nanodendrites. • The Pd 2 Ag 1 HNs exhibit excellent activity towards EGOR. • The PdAg HNs with rough surface can provide abundant catalytic active sites. [ABSTRACT FROM AUTHOR]

Platinum modified gold (Pt/Au) catalysts are evaluated for the electrooxidation of ethylene glycol (EG) and glucose (Glc). The Pt/Au catalysts are synthesized on an Au disk and supported Au/C particles through the galvanic displacement of a copper monolayer with Pt. The Pt/Au catalysts are compared to monometallic Pt and Au catalysts for the oxidation of EG and Glc in alkaline electrolyte. The Pt/Au disk has an onset potential for these reactions that is similar to Pt and is lower than Au. The supported catalysts are less active toward the electrooxidation of EG and Glc than the corresponding disk electrodes, but the Pt/Au/C also has an onset potential similar to Pt/C. In-situ FTIR is used to analyze the C–C bond scission in both reactions on the surfaces of Pt, Au, and Pt/Au disks. While the Pt/Au disk is found to have a low onset potential for the oxidation of EG, it does not produce as much CO 2 as bulk Pt. On the other hand, the FTIR results show that CO 2 is produced for the oxidation of Glc on the Pt/Au disk. These results show promise for the possibility of decreasing the amount of Pt needed for the electrooxidation of polyol molecules. [ABSTRACT FROM AUTHOR]

We report a graphene three-dimensional network (G3DN) structure on a Si substrate, which is used as Pt nanoparticle support for effective electrocatalytic oxidation of methanol and ethanol. The controllable Pt loading on the G3DN is conducted by a facile, repeatable and environmentally friendly approach. The influence of graphene architecture on electrocatalytic activities is comparatively investigated by loading the same amount of Pt on the G3DN and on commercial graphene sheets (CGS). The Pt/G3DN (0.01 mg Pt cm −2 ) electrode exhibits a tremendous electrocatalytic activity for the oxidation of methanol and ethanol with oxidation current of 910.11 mA mg Pt −1 and 246.69 mA mg Pt −1 respectively owing to its high density of three-dimensional active sites, wavy sheet-network channels and synergistic effect of Pt and graphene. The peak current density ratio of the forward to backward potential scan is 2.79 and 0.65 for the methanol and ethanol oxidation respectively. The results reveal excellent characteristics of the Pt/G3DN electrode, such as easy preparation, high catalytic activity, stability and tolerance toward poisoning effects for the electrooxidation of methanol. [ABSTRACT FROM AUTHOR]

Abstract: Kinetics and mechanism of formic acid (FA) oxidation on platinum and upd-lead ad-atoms modified platinum electrodes have been studied using unlabelled and deuterated compounds. Poisoning of the electrode surface by CO-like species was prevented by suppression of dissociative chemisorption of FA due to a fast competitive underpotential deposition of lead ad-atoms on the Pt surface from an acidic solution containing Pb2+ cations. Modification of the Pt electrode with upd lead induced a catalytic effect in the direct electrooxidation of physisorbed FA to CO2. With increasing degree of H/D substitution, the rate of this reaction decreased in the order: HCOOH > DCOOH ≥ HCOOD > DCOOD. HCOOH was oxidized 8.5-times faster on a Pt/Pb electrode than DCOOD. This primary kinetic isotope effect proves that the C–H- and O–H-bonds are simultaneously cleaved in the rate determining step. A secondary kinetic isotope effect was found in the dissociative chemisorption of FA in the hydrogen adsorption–desorption range on a bare Pt electrode after H/D exchange in the C–H bond, wherein the influence of deuterium substitution in the O–H group was negligibly small. Thus the C–H bond cleavage is accompanied by the C–OH and not the O–H bond split in the FA decomposition, producing CO-like species on the Pt surface sites. [Copyright &y& Elsevier]

Abstract: Porous Pd nanoparticles are successfully prepared by a rapid, one-step, and efficient route with high yield in aqueous solution. The developed method is very simple, just by mixing sodium tetrachloropalladate, polyvinylpyrrolidone and hydroquinone and heated at 70 °C for 15 min. The structure and composition are analyzed by transmission electron microscope, selected-area electron diffraction, inductively coupled plasma optical emission spectrometer, X-ray diffraction, energy dispersive X-ray spectrum and X-ray photoelectron spectroscopy. Electrochemical catalytic measurement results prove that the as synthesized porous Pd nanoparticles exhibit superior catalytic activity towards ethanol and formic acid electrooxidation. [Copyright &y& Elsevier]

Abstract: A novel core–shell structured AuPt@Pd/C catalyst for the electrooxidation of formic acid is synthesized by a pulse electrodeposition process, and the AuPt core nanoparticles are obtained by a NaBH4 reduction method. The catalyst is characterized with X-ray powder diffraction and transmission electron microscopy, thermogravimetric analysis, cyclic voltammetry, CO stripping and X-ray photoelectron spectroscopy. The core–shell structure of the catalyst is revealed by the increase in particle size resulting from a Pd layer covering the AuPt core, and by a negative shift in the CO stripping peaks. The addition of a small amount of Pt improves the dispersion of Au and results in smaller core particles. The catalyst's activity is evaluated by cyclic voltammetry in formic acid solution. The catalyst shows excellent activity towards the anodic oxidation of formic acid, the mass activity reaches 4.4 A mg−1 Pd and 0.83 A mg−1 metal, which are 8.5 and 1.6 times that of commercial Pd/C. This enhanced electrocatalytic activity could be ascribed to the good dispersion of Au core particles resulting from the addition of Pt, as well as to the interaction between the Pd shell layer and the Au and Pt in the core nanoparticles. [Copyright &y& Elsevier]

Carbon fiber cloth (CFC) supported Ni and Co electrodes are prepared by electrodeposition (Ni/CFC and Co/CFC). Their catalytic performance for H2O2 electrooxidation in KOH solution is investigated and compared with Au/CFC electrode. Ni/CFC electrode exhibits higher catalytic activity than Au/CFC and Co/CFC electrodes. The performance of a direct peroxide–peroxide fuel cell (DPPFC) with Ni/CFC anode and Pd/CFC cathode is examined. The cell shows a peak power density of 21.6 mW cm−2 at 20 °C and 53.8 mW cm−2 at 50 °C. The cell performance is improved with the increase of anolyte and catholyte flow rate and operation temperature. Results indicates that the performance of DPPFC with low-cost Ni/CFC anodes is comparable with those using precious metal anodes, e.g., Au/CFC and Pd/CFC. [ABSTRACT FROM AUTHOR]

Abstract: Nitrogen-doped acetylene carbon black (N-C) is prepared by annealing acetylene carbon black and melamine under the protection of N2 at different temperatures. The resultant N-C materials are used as the support of Pd catalyst (Pd/N-C) for formic acid electrooxidation (FAEO). The catalytic activity of the Pd/N-C catalyst towards FAEO is evaluated by cyclic voltammetry, COad stripping voltammetry and chronoamperometry. The results show that when the heat-treatment temperature of support is 900 °C, the corresponding catalyst, Pd/N-C-900, generate 2.84-fold and 0.96-fold higher activity than homemade and commercial Pd/C catalysts in 0.5 M H2SO4 and 0.5 M HCOOH solution. The COad stripping voltammetry results demonstrate that Pd/N-C-900 has much better resistance to CO poisoning. Moreover, the effect of formic acid concentration and the temperature on the Pd/N-C catalysts are also explored, which confirms the really enhanced performances for FAEO. It is founded that the doping of nitrogen results an increase in the performance for FAEO due to the improved Pd nanoparticles (Pd NPs) dispersion and the modified electronic effect. The results indicate that the Pd/N-C catalyst has great application prospect as a high-performance anode catalyst for direct formic acid fuel cells (DFAFCs). [Copyright &y& Elsevier]

Abstract: Tungsten carbide (WC) promoted palladium (Pd) and palladium–cobalt (Pd–Co) nanocatalysts are prepared and characterized for formic acid electrooxidation. The WC as the dopant to carbon supports is found to enhance the CO tolerance and promote the activity of the Pd-based catalysts for formic acid oxidation. Alloying of Pd with Co further improves the electrocatalytic activity and stability of the WC supported catalysts, attributable to a synergistic effect of the carbide support and PdCo alloy nanoparticles. [Copyright &y& Elsevier]

Abstract: Dendritic Pd is electrodeposited uniformly on carbon fiber cloth via a potential pulse technique. The electrode is characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffractometer, and it shows a unique open structure allowing the full utilization of Pd surface active sites. H2O2 electrooxidation in KOH solution and electroreduction in H2SO4 solution on the dendritic Pd electrode are studied by linear sweep voltammetry and chronoamperometry. The electrode exhibits a high catalytic performance for both H2O2 electrooxidation and electroreduction, and it outperforms the conventional electrode made with commercial Pd/C powder. KOH and H2SO4 in excess show no improvement to the activity of H2O2 oxidation and reduction, respectively. The overpotential at the same current density for H2O2 electrooxidation in alkaline solution is significantly lower than that for electroreduction in acid medium on the dendritic Pd electrode. [Copyright &y& Elsevier]

Abstract: Electrochemical oxidation of methanol on Pt/C and Pt–Ru/C electrocatalysts was studied by slow scan rate voltammetry at 130–190°C. The effects of partial pressures of water, methanol, and CO on the methanol electrooxidation rate were determined. It was found that methanol oxidation on Pt–Ru/C proceeds primarily via the “indirect” route through the formation of strongly adsorbed intermediate COads, while on Pt methanol electrooxidation occurs primarily via “direct” route through the formation of weakly adsorbed intermediates. At 140°C activity of Pt–Ru/C in methanol electrooxidation was found 2 orders of magnitude higher than that of Pt/C. Methanol oxidation reaction orders per water and methanol vapor pressures were determined. The main features of methanol electrooxidation both on Pt and Pt–Ru were accounted for assuming Langmuir–Hinshelwood mechanism of respective RDS. [Copyright &y& Elsevier]

Abstract: A detailed study aimed at clarifying the electrochemical behavior of Co/Al-LDH thin films, prepared on Pt electrode by electrodeposition at −0.9V, has been carried out. Reproducible thin and homogeneous films with variable amounts of LDH coated on the electrode surface have been achieved by varying the electrodeposition time (t =5, 10, 30 and 60s): 29.2±0.7, 37.9±1.4, 55.1±2.1 and 62.5±4.3μgcm−2, respectively. X-ray diffraction, spectroscopic techniques and the electrochemical quartz crystal microbalance analysis have been used to give an insight into the phase changes occurring when the as-prepared Co/Al-LDH thin films were oxidized and reduced by cycling the potential between 0 and 0.6V/SCE in 0.1M KOH. Our experiments demonstrate that the irreversible oxidation peak observed in the first cycle corresponds to the transformation of the Co(II)/Al-LDH phase in a γ-Co(III)OOH like phase. This resulting phase is stable under cycling and shows a pseudo-capacitive behavior with an estimated specific capacitance of 500Fg−1. [Copyright &y& Elsevier]

Abstract: SnO2 nanoflowers and nanorods have been synthesized by the hydrothermal method without using any capping agent. Both types of SnO2 nanostructures are selected as a support of Pt catalyst for methanol and ethanol electrooxidation. The synthesized SnO2 nanostructures and SnO2 supported platinum (Pt/SnO2) catalysts are characterized by X-ray diffraction, scanning electron microscope and high resolution transmission electron microscope. The electrocatalytic properties of the Pt/SnO2 and Pt/C catalysts for methanol and ethanol oxidation have been investigated systematically by typical electrochemical methods. The influence of SnO2 morphology on its electrocatalytic activity is comparatively investigated. The Pt/SnO2 flower-shaped catalyst shows higher electrocatalytic activity and better long-term cycle stability compared with other electrocatalysts owing to the multidimensional active sites and radial channels of liquid diffusion. [Copyright &y& Elsevier]

Abstract: Nowadays, the studies are focused on the search of better electrocatalysts that promote the complete oxidation of ethanol/bioethanol to CO2. To that end, amorphous bi-catalytic catalysts of composition Ni59Nb40Pt1−x Y x (Y=Cu, Ru, x =0.4% at.) have been developed, obtained by mechanical alloying, resulting in higher current densities and an improvement in tolerance to adsorbed CO vs. Ni59Nb40Pt1 catalyst. By using voltammetric techniques, the appearance of three oxidation peaks can be observed. The first peak could be associated with the electrooxidative process of ethanol/bioethanol to acetaldehyde, the second peak could be the oxidation of acetaldehyde to acetic acid, and the last peak might be the final oxidation to CO2. Chrono-amperometric experiments show qualitative poisoning of catalytic surfaces. However, the in situ Fourier Transformed Infrared Spectroscopy, FTIR, is used for the quasi-quantitative determination with which can be observed the appearance and evolution of different vibrational bands of carbonyl and carboxylic groups of different species, as it moves towards anodic potential in the electrooxidative process. [Copyright &y& Elsevier]

Abstract: Acetone is the main product of 2-propanol electrooxidation in both acid and alkaline electrolytes; it always co-exists with 2-propanol in the reaction solution due to its liquid nature. Whether acetone will affect the electrooxidation of 2-propanol has not been well documented, which is a key issue that needs to be addressed for the direct 2-propanol fuel cell. In this study, the influence of acetone on the electrooxidation of 2-propanol in alkaline medium is investigated, using state-of-the-art Pd electrode, by cyclic voltammetry and chronoamperometry. The electrode is prepared using a chemical replacement method, by dipping nickel foam into acidified PdCl2 solution, and characterized by scanning electron microscopy. We found that the presence of acetone adversely affects electrooxidation performance of 2-propanol and substantially reduces the oxidation current of 2-propanol on Pd in alkaline medium. The acetone poisoning effect is interpreted by a competitive adsorption mechanism, in which acetone adsorbs onto Pd surface and occupies the active sites for 2-propanol electrooxidation, leading to a significant decrease in the number of these sites for 2-propanol electrooxidation. The results of this study point out that efficient electrocatalysts for 2-propanol electrooxidation in alkaline electrolytes must be non-adsorptive to acetone besides being highly active to 2-propanol oxidation. [ABSTRACT FROM AUTHOR]

Abstract: Pd nanoparticles supported on the WO3/C hybrid are prepared by a two-step procedure and the catalysts are studied for the electrooxidation of formic acid. For the purpose of comparison, phosphotungstic acid (PWA) and sodium tungstate are used as the precursor of WO3. Both the Pd–WO3/C catalysts have much higher catalytic activity for the electrooxidation of formic acid than the Pd/C catalyst. The Pd–WO3/C catalyst prepared from PWA shows the best catalytic activity and stability for formic acid oxidation; it also shows the maximum power density of approximately 7.6mWcm−2 when tested with a small single passive fuel cell. The increase of electrocatalytic activity and stability is ascribed to the interaction between the Pd and WO3, which promotes the oxidation of formic acid in the direct pathway. The precursors used for the preparation of the WO3/C hybrid support have a great effect on the performance of the Pd–WO3/C catalyst. The WO3/C hybrid support prepared from PWA is beneficial to the dispersion of Pd nanoparticles, and the catalyst has potential application for direct formic acid fuel cell. [Copyright &y& Elsevier]

Abstract: A carbon nanotubes (CNTs) supported composite catalyst consisting of Pd and Ni (Pd–Ni/CNT) is synthesized by a chemical method. The electrocatalytic activities of Pd/CNT, Ni/CNT and Pd–Ni/CNT toward the hydrazine oxidation reaction (HOR) are evaluated by linear sweep voltammetry, electrochemical impedance spectroscopy and polarization measurement. The composite catalyst demonstrates higher electrocatalytic activity than its single-constituent catalysts due to the synergy between Ni and Pd. The Pd addition in the composite catalyst prevents oxidation of Ni so that the Pd–Ni/CNT electrode exhibits smaller reaction resistance to the HOR than the Ni/CNT and Pd/CNT electrodes. [ABSTRACT FROM AUTHOR]

Abstract: The electrooxidation behavior of dimethyl ether (DME) dissolved in acidic, neutral or alkaline anolyte has been studied. The cyclic voltammetry measurements reveal that DME in alkaline anolyte demonstrates higher electrooxidation reactivity than that in acidic or neutral anolyte. With increasing the NaOH concentration in the anolyte, the electrooxidation reactivity of DME can be further improved. Direct dimethyl ether fuel cells (DDFCs) are assembled by using Nafion membrane as the electrolyte, Pt/C as the cathode catalyst, and Pt–Ru/C as the anode catalyst. It is found that the use of alkaline anolyte can significantly improve the performance of DDFCs. A maximum power density of 60mWcm−2 has been achieved when operating the DDFC at 80°C under ambient pressure. [Copyright &y& Elsevier]

Abstract: Carbon-supported Pd4Au- and Pd2.5Sn-alloyed nanoparticles were prepared by a chemical reduction method, and characterized by a wide array of experimental techniques including mass spectrometry, transmission electron microscopy, and X-ray diffraction spectroscopy. Ethanol electrooxidation on the as-synthesized catalysts and commercial Pt/C was then investigated and compared in alkaline media by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy studies at room temperature. Voltammetric and chronoamperometric measurements showed higher current density and longer term stability in ethanol oxidation with the palladium alloy nanocatalysts than with the commercial one. Electrochemical impedance spectroscopy and Tafel plots were employed to examine the charge-transfer kinetics of ethanol electrooxidation. The results suggest that whereas the reaction kinetics might be somewhat more sluggish on the Pd-based alloy catalysts than on commercial Pt/C, the former appeared to have a higher tolerance to surface poisoning. Overall, the Pd-based alloy catalysts represent promising candidates for the electrocatalytic oxidation of ethanol, and Pd4Au/C displays the best catalytic activity among the series for the ethanol oxidation in alkaline media. [Copyright &y& Elsevier]

Abstract: Carbon nanotubes (CNTs) supported PtPd hollow nanospheres have been prepared by a replacement reaction between sacrificial cobalt nanoparticles and PtCl6 2−, Pd2+ ions. The morphology, elemental composition, structure and electrocatalytic properties of the PtPd hollow nanospheres have been investigated by transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and typical electrochemical methods, respectively. The results indicate that the CNTs supported PtPd hollow nanospheres have excellent electrochemical properties for the electrooxidation of formic acid (high electrocatalytic activity and excellent stability) due to the high surface area resulted from the hollow nanosphere structure with porous shell. [Copyright &y& Elsevier]

Abstract: γ-MnO2 nanoparticles-coated polyaniline (PANI) nanofibers on carbon electrode were prepared by potentiodynamic electrochemical deposition of PANI and MnO2 from a single pot. Higher thermal stability of the resulting nanocomposites and their activity for formic acid oxidation permits the realization of a platinum-free anode for formic acid fuel cells. [Copyright &y& Elsevier]

Abstract: This research aims to investigate Pd-based catalysts as a replacement for Pt-based catalysts for ethanol electrooxidation in alkaline media. The results show that Pd/C has a higher catalytic activity and better steady-state behaviour for ethanol oxidation than that of Pt/C. The effect of the addition of CeO2 and NiO to the Pt/C and Pd/C electrocatalysts on ethanol oxidation is also studied in alkaline media. The electrocatalysts with a weight ratio of noble metal (Pt, Pd) to CeO2 of 2:1 and a noble metal to NiO ration 6:1 show the highest catalytic activity for ethanol oxidation. The oxide promoted Pt/C and Pd/C electrocatalysts show a higher activity than the commercial E-TEK PtRu/C electrocatalyst for ethanol oxidation in alkaline media. [Copyright &y& Elsevier]

Abstract: Electrochemical impedance spectroscopy (EIS) along with cyclic voltammetry (CV) has been applied as a tool for the mechanistic investigation of methanol oxidation on nanoparticulate PtRu fuel cell anodes of a commercially available state of the art membrane electrode assembly (MEA). The spectra could be fitted to a circuit derived analytically for multi-step single adsorbed intermediate reactions. The analysis has indicated that methanol adsorption and surface blocking occur below the onset and the surface is ‘poisoned’ to the highest degree just before the onset, implying that the removal of residues before the onset, if any, is slower compared to the formation. The onset potential is marked by a sudden change in the mechanism as the impedance becomes pseudoinductive. It has also been demonstrated that EIS can be applied for analyzing and singling out different contributions behind electrode performance for methanol oxidation reaction under fuel cell operating condition. [Copyright &y& Elsevier]

Abstract: A new catalyst electrode was prepared in which Pt particles were homogeneously distributed into a poly(3,4-ethylenedioxythiophene)–poly(styrene sulfonic acid) (PEDOT–PSS) matrix. Catalytic activity and stability for the oxidation of methanol were studied by using cyclic voltammetry and chronoamperometry. For comparative purposes, bulk Pt and PEDOT–PSS based electrodes were fabricated and tested. Enhanced electrocatalytic activity toward the oxidation of methanol was noticed when Pt particles were embedded into the PEDOT–PSS matrix. A high catalytic current for methanol oxidation (2.51mAcm−2) was found for the PEDOT–PSS–Pt electrode in comparison to bulk Pt electrode (0.45mAcm−2) at +0.6V (versus Ag/AgCl). The enhanced electrocatalytic activity might be due to the dispersion of Pt particles into the PEDOT–PSS matrix and the synergistic effects between the dispersed Pt particles and the PEDOT–PSS matrix. The morphology and crystalline behavior of PEDOT–PSS–Pt and simple ITO/Pt films were determined by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) and correlated with the enhanced electrocatalytic activity for the Pt-dispersed PEDOT–PSS electrode. [Copyright &y& Elsevier]

Abstract: The electrooxidation of methoxy methane (dimethyl ether) was studied at different Pt-based electrocatalysts in a standard three-electrode electrochemical cell. It was shown that alloying platinum with ruthenium or tin leads to shift the onset of the oxidation wave towards lower potentials. On the other hand, the maximum current density achieved was lower with a bimetallic catalyst compared to that obtained with a Pt catalyst. The direct oxidation of dimethoxy methane in a fuel cell was carried out with Pt/C, PtRu/C and PtSn/C catalysts. When Pt/C catalyst is used in the anode, it was shown that the pressure of the fuel and the temperature of the cell played important roles to enhance the fuel cell electrical performance. An increase of the pressure from 1 to 3bar leads to multiply by two times the maximum achieved power density. An increase of the temperature from 90 to 110°C has the same effect. When PtRu/C catalyst is used in the anode, it was shown that the electrical performance of the cell was only a little bit enhanced. The maximum power density only increased from 50 to 60mWcm−2 at 110°C using a Pt/C anode and a Pt0.8Ru0.2/C anode, respectively. But, the maximum power density is achieved at lower current densities, i.e. higher cell voltages. The addition of ruthenium to platinum has other effect: it introduces a large potential drop at relatively low current densities. With the Pt0.5Ru0.5/C anode, it has not been possible to applied current densities higher than 20mAcm−2 under fuel cell operating conditions, whereas 250 and almost 400mAcm−2 were achieved with Pt0.8Ru0.2/C and Pt/C anodes. The Pt0.9Sn0.1/C anode leads to higher power densities at low current densities and to the same maximum power density as the Pt/C anode. [Copyright &y& Elsevier]

Abstract: Tungsten trioxide microspheres of 2–4μm diameter have been prepared by controlled oxidation of tungsten carbide microspheres. These microspheres are characterized by XRD, SEM, and HRTEM. The microspheres are made of WO3 nanoparticles with an average diameter of around 15nm. Platinum supported on these WO3 microspheres exhibits higher and stable electrocatalytic activity for methanol oxidation by a factor of around two, than commercial 20wt.% Pt–Ru/Vulcan-XC72 carbon and 20wt.% Pt–Ru/carbon microspheres even without Ru. The higher activity is attributed to the better tolerance to carbon monoxide of the Pt/WO3 catalyst. These Pt/WO3 microspheres appear to be a promising alternative anode material for direct methanol fuel cells. They replace Ru entirely and save a substantial amount of Pt in the Pt–Ru electrode that is presently employed in fluel cells. [Copyright &y& Elsevier]

Abstract: Formic acid fuel cells offer exciting prospects for powering portable electronic and MEMS devices. Pd-based catalysts further improve the performance of direct formic acid fuel cells while reducing catalyst costs over Pt-based catalysts. This study investigates several Pd-based catalysts, both unsupported and carbon-supported, and compares the electrochemical results with results obtained in an operating fuel cell. Power densities of up to 260mWcm−2 were achieved in a fuel cell at 750mA operating at 30°C. Carbon-supported catalysts and addition of other metals, such as gold, show potential in further improving the performance of Pd-based catalysts. [Copyright &y& Elsevier]

Abstract: The electrocatalytic oxidation of methanol at a (Pb) lead electrode modified by Pt, Pt–Ru and Pt–Sn microparticles dispersed into poly(o-phenylenediamine) (PoPD) film has been investigated using cyclic voltammetry as analytical technique and 0.5M sulfuric acid as supporting electrolyte. It has been shown that the presence of PoPD film increases considerably the efficiency of deposited Pt and Pt alloys microparticles toward the electrocatalytic oxidation of methanol. The catalytic activity of Pt particles is further enhanced when Ru and especially Sn, is co-deposited in the polymer film. The effects of various parameters such as concentration of methanol, medium temperature as well as the long term stability of modified electrodes have also been investigated. [Copyright &y& Elsevier]

Abstract: l-Ascorbic acid (AA) has been shown to undergo oxidation on polyaniline (PANI) without a platinum-group catalyst. A direct ascorbic acid fuel cell (DAAFC) has been assembled by employing an anode coated with PANI catalyst. From the experimental studies using cyclic voltammetry, amperometry and IR spectroscopy, it has been concluded that PANI facilitates the oxidation of AA. It has been possible to achieve a maximum power density of 4.3mWcm−2 at a load current density of 15mAcm−2 at 70°C. As both AA and PANI are inexpensive and environmental-friendly, the present findings are expected to be useful for the development of cost-effective DAAFCs for several low power applications. [Copyright &y& Elsevier]

The activity of unsupported ternary PtRuMeOx (Me=W, Mo, V) high surface area catalysts towards methanol oxidation under fuel cell relevant conditions, at constant potential and elevated temperature of 60 °C, was investigated by the thin-film electrode method. CO-stripping experiments for actual surface area detection, using differential electrochemical mass spectrometry (DEMS) to evaluate the amount of adsorbed CO, show that the electrochemically active area of the particle surface is significantly smaller than the total particle surface area determined by N2 BET measurements, indicating that part of their surface consists of MeOx. The specific surface activity of the catalysts towards methanol oxidation at 60 °C, normalized to the current density per square centimeter of electrochemically active noble metal surface, decreases in the order PtRuVOx>PtRuMoOx>PtRu>PtRuWOx=PtRu (E-TEK). Apparently, the surface oxide leads to an acceleration of the methanol oxidation reaction, which is, however, partly compensated by a decrease in active surface area. [Copyright &y& Elsevier]

Abstract: Borazane (BH3NH3) is a stable and low-toxic crystalline solid with possibly the highest hydrogen content (19.5wt.%) in chemical compounds. In this communication, we report for the first time the electrooxidation of borazane and a novel direct fuel cell using alkaline borazane solution as alternative fuel. Of particular importance in this work is that non-platinum catalysts were applied for both the anode and the cathode. After a screening of a number of candidates (including Pt, Au, Ni, Cu, etc.), Ag was found to be a highly efficient catalyst for anodic oxidation of borazane, and MnO2 turned out to be a good cathode catalyst showing borazane-tolerance. The energy density of the fuel released by such a preliminary direct fuel cell was ca. 2000mAhg−1 at 1mAcm−2 and 0.9V at room temperature. [Copyright &y& Elsevier]