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Although great success has been made in the design of welldefined nanocrystals (NCs) with various morphologies, a facile method to prepare desirable NCs with large active surface areas and unique facets remains an arduous challenge. Herein, we demonstrate a facile method for the successful synthesis of high-quality PtFe nanodendrites with a multibranched architecture; these nanodendrites have an abundance of exposed surface active sites that are available for ethanol molecules. Detailed study of its electrocatalytic properties revealed that the resultant superbranched PtFe nanocatalysts displayed superior electrocatalytic activity towards ethanol oxidation with unprecedentedly high mass/specific activities of 3692.5 mAmg-1 and 7.02 mAcm-2; these values are 9.3 and 10.0-fold higher than those of a commercial Pt/C catalyst, signifying that the these nanodendrites may serve as highly efficient catalysts for fuel cells and beyond. [ABSTRACT FROM AUTHOR]

Abstract: Precise control of structures offers a great opportunity to efficiently tune the catalytic performance of nanomaterials, enhacing both their activity and durability. Herein, we achieve a new class of Pt islands on 3 D nut‐like PtAg nanocrystals by exploiting the lower electronegativity of Ag in conjunction with the galvanic replacement of catalytically active Pt to Ag. Such nanostructures coated with Pt nanoparticles, exhibiting exposed facets, and active surface composition enhance formic acid oxidation electrocatalysis with optimized PtAg1 nut‐like catalysts and achieved a factor of 4.0 and 2.4 in mass and specific activities (1728.3 mA mg−1 and 3.31 mA cm−2) relative to those of the commercial Pt/C (431.2 mA mg−1 and 1.41 mA cm−2), respectively. Moreover, such 3 D PtAg1 nut‐like catalysts also display great enhancement in durability with less decay for at last 500 cycles, showing a great potential to serve as promising catalysts for fuel cells and other applications. Our work provides a fundamental insight on the effect of the morphology toward liquid fuel electrooxidation, which may pave a new way for the fabrication of highly efficient electrocatalysts for fuel cells. [ABSTRACT FROM AUTHOR]

Abstract: The research of active and stable electrocatalysts toward liquid‐fuel oxidation reaction is of great significance for the large‐scale commercialization of fuel cells. Although extensive efforts have been devoted to pursuing high‐performance nanocatalysts for fuel cells, both the high cost and sluggish reaction kinetics have been two major drawbacks that limited its commercial development. In this regard, we demonstrated a facile solvothermal method for the syntheses of an advanced class of PtCu nanocatalysts with a unique pentangle‐like shape. By combining the merits of a highly active surface area as well as the synergistic and electronic effects, the as‐prepared pentangle‐like Pt3Cu nanocatalysts showed superior electrocatalytic activity towards ethylene glycol oxidation with a mass and specific activities of 5162.6 mA mg−1 and 9.7 mA cm−2, approximately 5.0 and 5.1 times higher than the commercial Pt/C, respectively. More significantly, the Pt3Cu pentangle also showed excellent long‐term stability with less activity decay and negligible changes in structure after 500 cycles, indicating another class of anode catalysts for fuel cells and beyond. [ABSTRACT FROM AUTHOR]

A highly efficient PdCu alloy nanocatalyst has been designed and synthesized, which exhibited excellent selectivity and activity toward ethylene glycol (EG) oxidation reaction with a low loading of electrocatalyst. The results of characterization show that the atom ratio of 1:1 (Pd:Cu) as well as the addition of polyvinyl pyrrolidone (PVP) and potassium bromide (KBr) contributed to the unique morphology of the as-prepared PdCu catalyst. Owing to the flower-like nanostructure and the synergistic effect between Pd and Cu, PdCu electrocatalyst has distinct enhancement in electrocatalytic performance whose forward peak current density is almost 3.2 and 4.3 times higher than that of pure Pd and commercial Pd/C electrocatalysts. We put forward that the prepared PdCu catalyst may have promising and alternative applications in direct EG alkaline fuel cells. [ABSTRACT FROM AUTHOR]

Although substantial investigations on exploring highly-efficient Pt-based materials for serving as the desirable anode electrocatalysts for fuel cells have been carried out over decades, while the large-scale commercial application remains a formidable challenge. To this end, we herein combine the advantages of both compositions and morphology to successfully fabricate the fascinating satellite-like PtAu nanocrystals (PtAu NCs) with dendritic shell via a facile wet-chemical approach. A series of electrochemical measurements have revealed that the as-prepared binary PtAu NCs possessed the outstandingly high electrocatalytic activity toward ethylene glycol oxidation reaction (EGOR) with the mass activity of 4856.2 mA/mg, 4.47-fold enhancements than that of commercial Pt/C. Moreover, the satellite-like PtAu NCs can endure with less activity decay under durability test, demonstrating a novel class of Pt-based catalysts with excellent electrocatalytic performances for fuel cells and beyond. We do believe that both the synthetic strategy and the catalysts we developed in this work can well boost the commercial development of direct fuel cell. [ABSTRACT FROM AUTHOR]

Advancing the intrinsic catalytic performances of electrocatalysts is believed to be an efficient approach for alleviating the energy crisis and environmental pollution. However, many drawbacks of the newly established catalysts such as large size, poor corrosion resistance, and anti-poisoning make them exhibit limited electrocatalytic performances. To address these challenges, we herein embody the advantages of both composition and morphology to successfully fabricate self-supported worm-like PdAg nanoflowers (PdAg NFs) with the assistance of cetyltrimethylammonium bromide. Such special PdAg NFs with a high active surface area of 42.36 m2 g−1 display much better electrocatalytic performances with mass and specific activities of 5545 mA mg−1 and 12.82 mA cm−2 towards ethylene glycol oxidation, which are 6.9 and 2.1 times higher than that of commercial Pd/C, respectively. Our efforts in this work may open up a new way to maximize the electrocatalytic performance of catalysts by designing and adjusting their morphologies. We also trust that the electrocatalysts fabricated in this work can be applied as potential anodic catalysts and beyond. [ABSTRACT FROM AUTHOR]

In this study, three-dimensional (3D) porous PdCu bimetallic alloys were synthetized through a facile one-pot method by employing hydrazine hydrate, polyvinylpyrrolidone and sodium bromide as the reducing agent, surfactant and structure-directing agent, respectively. The network nanostructure offers large open pores and special morphology which plays an important role in strengthening ethanol electrocatalytic activity and durability. The as-prepared 3D network PdCu nanocatalyst displays greatly enhanced electrocatalytic activities towards ethanol oxidation in alkaline medium. Notably, the catalyst with Pd:Cu atomic ratio of 1:1 exhibits the highest electrocatalytic activity, its mass activity of ethanol oxidation reaches 3362.50 mA/mg, which is 7.20 times than that of commercial Pd/C catalyst. This study suggests that introduction of copper could possibly improve the feasibility of the direct ethanol fuel cells for real world applications by improving electrocatalytic activity and lowering production cost. [ABSTRACT FROM AUTHOR]

A novel composite catalyst of Pd nanoparticles supported on 1,6-hexanediamine-functionalized reduced graphene oxide (HD-RGO) has been successfully synthesized by a facile chemical method. The as-synthesized composite catalyst has been extensively characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and electrochemical tests. TEM images show that Pd nanoparticles with smaller diameters of (3.30±1.20) nm are more evenly dispersed on the HD-RGO surface than those supported on RGO. Electrochemical tests reveal that the as-prepared Pd/HD-RGO catalyst displays higher electrocatalytic activity, better tolerance, and better electrochemical stability toward ethanol oxidation in alkaline media in comparison with Pd/RGO and commercial Pd/C catalysts. The Pd/HD-RGO catalyst may be a promising potential catalyst in direct ethanol fuel cells. [ABSTRACT FROM AUTHOR]

A facile, eco-friendly method for the synthesis of gold/platinum catalysts through electrodeposition of platinum nanoparticles, followed by the deposition of solutions of HAuCl4 onto the surface of pre-prepared platinum for a galvanic replacement reaction, is reported. Different molar ratios of bimetallic structures of platinum and gold could be easily achieved and characterized by energy-dispersive X-ray spectroscopy, SEM, and XRD. Electrochemical measurements reveal that the electrocatalytic activities of these series of gold/platinum catalysts towards formic acid oxidation reaction are superior to that of pure platinum. In addition, the formic acid oxidation route is related to the molar ratio of gold to platinum, which can be ascribed to the influence of gold. The gold/platinum catalyst with a platinum to gold atomic ratio of 2.51:1 exhibits maximum activity. Moreover, this optimized molar ratio shows a highly stable electrocatalytic activity for CO antipoisoning effects. These experimental results suggest that the prepared gold/platinum catalysts have great potential for applications in fuel cells. [ABSTRACT FROM AUTHOR]

In the present work, a novel electrode composed of TiO, reduced graphene oxide (RGO) and Pt nanoparticles on carbon fiber (CF), denoted as Pt/RGO/TiO/CF, has been fabricated successfully and employed as a photo-electrocatalyst for methanol oxidation in alkaline media. The spherical TiO nanoparticles are loaded on CF surface by an in situ method and wrapped by the gauze-like RGO. Meanwhile, the RGO effectively extends the absorption edge to visible light region based on the UV-vis diffuse reflectance absorption spectra (DRS) and promotes the good dispersion of Pt nanoparticles electro-deposited on the surface of RGO-wrapped TiO. The as-prepared Pt/RGO/TiO/CF electrode shows enhanced electrocatalytic activity and stability compared with Pt/TiO/CF and Pt/CF electrodes both with and without light irradiation. The RGO plays an important role for the enhancement of electrocatalytic and photo-electrocatalytic performance. Moreover, Pt/RGO/TiO/CF presents a higher photo-electrocatalytic activity for methanol oxidation with light irradiation than that without light irradiation due to the synergistic effect among them. [ABSTRACT FROM AUTHOR]

The support materials play a critical role for the electrocatalytic oxidation of ethanol on precious metal catalysts in fuel cells. Here, we report the poly(3,4-ethylenedioxythiophene) combined with reduced graphene oxide (PEDOT-RGO) as the support of Pd nanoparticles (NPs) for ethanol electrooxidation in alkaline medium. The as-prepared Pd/PEDOT-RGO composite catalysts are characterized by Raman spectrometer, X-ray diffraction, transmission electron microcopy, and scanning electron microcopy. PEDOT-RGO composite with the porous structure facilitates the dispersion of Pd NPs with a smaller size leading to the increase of electrochemical active surface area. The electrochemical properties and electrocatalytic activities of Pd/PEDOT-RGO hybrid are evaluated by cyclic voltammetry, chronoamperometry, CO stripping voltammetry, electrochemical impedance spectroscopy (EIS) and Tafel analysis. The results suggest that Pd/PEDOT-RGO hybrid shows a higher electrocatalytic activity, a better long-term stability, and the poisoning tolerance for the ethanol electrooxidation than Pd on carbon black. EIS and Tafel analysis indicate that PEDOT-RGO improves the kinetics of ethanol electrooxidation on the Pd NPs and is an efficient support in fuel cells. [ABSTRACT FROM AUTHOR]

Au/Pt bimetallic core/shell nanoparticles that were stabilized by polyaryl ether trisacetic acid ammonium chloride dendrons (G3NACl) were synthesized and used as catalysts for the hydrogenation of 3-phenoxybenzaldehyde to 3-phenoxyphenyl methanol and nitrobenzenes to anilines. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-visible absorption spectroscopy revealed that Au/Pt bimetallic nanoparticles with a 6-nm Au core and average overall diameters of 9.0 ± 2.4 nm, 10.4 ± 2.8 nm, and 13.0 ± 3.2 nm for Au75Pt25@G3NACl, Au50Pt50@G3NACl, and Au25Pt75@G3NACl, respectively, had formed. Au/Pt bimetallic nanoparticles showed higher catalytic activity for the hydrogenation of nitrotoluenes to anilines and 3-phenoxybenzaldehyde to 3-phenoxyphenyl methanol as compared to monometallic platinum nanoparticles and physical mixtures of monometallic Pt and Au nanoparticles. The higher activity of the Au/Pt bimetallic nanoparticles may be attributed to the fact that the gold core attracts electrons from platinum. The electron-deficient platinum shell may favor the adsorption of the substrate with polar carboxyl groups. [ABSTRACT FROM AUTHOR]

Reasonable design of Pd-based catalysts with specific composition and morphology is of great importance for promoting the commercial application. of direct alcohol fuel cells (DAFCs). Recently, two-dimension (2D) with high density of defects and massive low-coordinated surface atom has become research highlights in the field of catalysis. Herein, we report a wet chemical method for synthesizing PdCu nanosheets with abundant wrinkles. The ultrathin two-dimensional structure endows catalysts plentiful catalytic active sites and large specific surface area, improving atomic utilization efficiency. The formation of bimetallic PdCu alloy structure leads to the adjustment of Pd electronic structure, resulting in lattice compression effect. Benefitting from the structural and compositional characteristics, PdCu nanosheets (NSs) exhibits excellent electrocatalytic performance for ethylene glycol oxidation reaction (EGOR) and glycerol oxidation reaction (GOR) with the mass activity of 7031 mA mg−1/5117 mA mg−1, which is 4.4/3.9 times higher than that of commercial Pd/C catalysts. Furthermore, the remained mass activity of PdCu NSs is 3991/3851 mA mg−1 after the durability measurement for EGOR/GOR, which confirm PdCu NSs possesses superior stability. We believe that our synthetic strategy could provide robust reference for the development of high-performance eletrocatalysts. [Display omitted] • PdCu nanosheets were prepared by a facile solvothermal method. • The PdCu NSs provide ideal electrocatalytic active sites. • The PdCu NSs exhibited excellent electrocatalytic performance toward EGOR and GOR. [ABSTRACT FROM AUTHOR]

Ethylene glycol oxidation reaction (EGOR) is a key anode reaction in direct ethylene glycol fuel cells (DEGFCs). Herein, 2D semiconductor bismuth tungstate (Bi2WO6) nanosheets are facilely prepared and used as carriers for the deposition of platinum nanoparticles (Pt NPs). The resultant material is used as the working electrode in the application of DEGFCs. Due to the excellent absorption property of Bi2WO6 in visible light, the optimized Pt‐Bi2WO6 electrode (Pt at 20 wt%) shows improved catalytic activity and stability with visible‐light illumination. The current density using the Pt‐Bi2WO6 electrode reaches 492.5 mA mg−1Pt with visible‐light irradiation, which is about 4.2 fold higher in comparison with the same electrode in dark conditions. This 2D sheet‐like support, together with the visible‐light response of Bi2WO6, induces the deposition of ultra‐small sizes of Pt (5.4 nm) and the synergistic effect of electrocatalytic and photocatalytic ethylene glycol oxidation, thus greatly improving the photoelectric catalytic property of EGOR. [ABSTRACT FROM AUTHOR]

3D PdAg superstructures composed of hollow interior and 2D nanosheets shell, serving as highly active and selective EOR catalyst. [Display omitted] • We proposed for the first time that the Pd-Ag system facilitate the complete oxidation of ethanol. • A facile one-pot synthesis has been proposed for the synthesis of a holllow 3D open structure. • The 3D hollow PdAg superstructures achieve highly selective ethanol electrooxidation. Direct ethanol fuel cells (DEFCs) have been considered as future power devices for many portable applications. The ethanol oxidation reaction (EOR), that is, a multielectron process, suffers from low efficiency owing to the high selectivity to the 4e− pathway (C2 pathway) and low selectivity to the 12e− pathway (C1 pathway). The preparation of efficient catalysts with high C1 pathway selectivity is regarded as a promising and fascinating field. Herein, we first advance a one-pot synthesis of 3D PdAg superstructures (SSs) with a hollow interior and ultrathin nanosheet shell. PdAg SSs achieve a mass activity of 5.27 A mg−1 for the alkaline EOR and a Faraday efficiency of 22.7 % for the C1 pathway, which is 5.7 and 7.5 times higher than that of commercial Pd/C, respectively. Mechanism studies confirm that the construction of the Pd-Ag system greatly facilitates the oxidation of the C1 intermediates (*CH 3 and *CO) and enhances the C C bond cleavage ability of the catalyst. This work not only highlights an active Pd-based catalyst for the selective EOR, but also sheds light on the formation of 3D open nanostructure via self-assembly of 2D nanosheets. [ABSTRACT FROM AUTHOR]

A novel CoTe-C composite has been designed and prepared as a support of Pd catalyst for the electrooxidation of ethylene glycol. [Display omitted] • The CoTe-C composite has been fabricated as a support of Pd catalyst for the ethylene glycol oxidation reaction (EGOR) for the first time. • The effect of CoTe-C carrier on electrocatalytic performance for EGOR has been studied. • The Pd/CoTe-C catalyst exhibits high catalytic performance and stability for EGOR in alkaline medium. The development of highly active and earth-rich electrocatalysts remains a formidable challenge for the commercialization of fuel cells. Herein, a composite carrier composed of cobaltous telluride (CoTe) and carbon (C) has been designed for the first time to enhance the electrocatalytic performance of palladium (Pd) nanoparticles (NPs) for the electro-oxidation of ethylene glycol (EG). Remarkably, the mass activity for the as-prepared Pd/CoTe-C catalyst during the ethylene glycol oxidation reaction (EGOR) is found to reach up to 3917.3 mA mg−1, which is 2.2 times higher than that of Pd/Co-C (1785.0 mA mg−1) and 4.1 times greater than that of commercial Pd/C catalyst (962.4 mA mg−1), exceeding that obtained for most Pd-based electrocatalysts reported thus far. In particular, the Pd/CoTe-C catalyst shows better electrochemical stability toward the EGOR than the Pd/Co-C and commercial Pd/C catalysts. Thus, the Pd/CoTe-C electrocatalyst is expected to exhibit broad application prospects in the field of fuel cells. [ABSTRACT FROM AUTHOR]

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]

Abstract: A novel composite catalyst, Pt nanoparticles supported on poly(5-nitroindole) (Pt/PNI), has been successfully prepared by the electrochemical method and used for the electrooxidation of methanol in alkaline media. As-prepared Pt/PNI was characterized by SEM, EDX and electrochemical methods. The results of the catalytic activity for methanol oxidation showed that Pt/PNI had higher catalytic activity and stronger poisoning-tolerance than Pt/Pt, Pt/GC and the common Pt electrode. The effects of different parameters related to the methanol oxidation reaction kinetics, such as Pt loading, mass of PNI film, concentration of methanol and KOH, potential scan rate, have also been investigated. The present study showed a promising choice of Pt/PNI as composite catalyst for methanol electrooxidation in alkaline medium. [Copyright &y& Elsevier]

[Display omitted] Modifying the electronic structure and optimizing the geometric structure can expeditiously tune the electrocatalytic properties of catalysts, resulting in considerably enhanced electrocatalytic performance towards electrocatalytic oxidation of liquid fuels. We herein report a simple synthetic strategy to prepare Bi-doped 3D taraxacum-like Pd nanocages (NCs) composed of porous nanosheets, which possess high surface areas and strong synergistic effects. Notably, a trace of Bi diffuses into the lattice of Pd and increases the electronic effects of the surface of Pd, endowing PdBi-0.5 NCs/C with superior electrocatalytic performance towards ethanol oxidation reaction (EOR). The mass activity and specific activity of PdBi-0.5 NCs/C were 3494.8 mA mg Pd −1 and 10.37 mA cm−2, being 4.08- and 4.82- fold enhancements as compared with commercial Pd/C, respectively. Moreover, the highly open porous 3D nanocages structure with rich active sites and defects can also facilitate the mass/electron transfer to favor the EOR kinetics. [ABSTRACT FROM AUTHOR]

Direct fuel cells are regarded as the most portable device for alleviating the problems of the energy dilemma and environmental disruption. Although direct fuel cells have a number of advantages, the lack of highly-efficient anode catalysts inhibits their wide application. To address this challenge, we report a facile one-pot method to fabricate a series of ultrathin platinum-cobalt (Pt-Co) nanowires with different proportions. The as-prepared catalysts all have one-dimensional ultrathin nanowire structures with high yields. Among all these catalysts, the ultrathin Pt 89 Co 11 nanowires with optimized compositions, whose diameters are 1.8 nm on average, show the best catalytic activity for the glycerol oxidation reaction in alkaline conditions, and their mass and specific activities reach 4573.0 mA mg−1 and 11.9 mA cm−2, which are 5.4 and 3.6 times higher than those of commercial Pt/C catalysts, respectively. The as-obtained Pt 89 Co 11 nanowires are also the most durable nanowires according to long-term stability tests. This method may provide guidelines for the preparation of other Pt-based bimetallic nanowires, which could somewhat accelerate the development and commercialization of catalysts for fuel cells. [ABSTRACT FROM AUTHOR]

Great research attention is raised in the field of direct alcohol fuel cells due to their advantages such as potential for clean, renewability, and high energy density. However, the preparation and optimization of high-efficiency anode electrocatalysts are highly desirable yet challenging, which is an essential part in fuel cells. We thereby design a simple but efficient method and then synthesize a series of novel one dimension PtNi nanorods electrocatalysts. The as-prepared PtNi nanorods exhibit excellent electrocatalytic performance towards alcohol oxidations in alkaline medium. The Pt 3 Ni nanorods with optimized composition show the best mass and activity of 4601.5 mA mg−1 (11.4 mA cm−2) and 7260 mA mg−1 (18.1 mA cm−2) towards glycerol oxidation reaction and ethylene glycol oxidation reaction respectively, 4.6 (5.4) and 6.1 (7.2) times higher than commercial Pt/C catalysts. The present work in situ offers a practical synthetic approach of electrocatalysts and their better catalytic properties in alcohol oxidation reactions, which has a promoting effect for development of liquid fuel cells. Image 1 • The PtNi nanorods with uneven surface provide abundant catalytic active sites. • The synergistic effect and 1D structure help enhance catalytic activity. • The Pt 3 Ni nanorods exhibit superior catalytic performance for GOR and EGOR. [ABSTRACT FROM AUTHOR]

Pursuing high-effective electrocatalysts is of paramount importance yet a great challenge, drawbacks such as irregular morphology, weak corrosion resistance, and poor anti-poisoning that limited their catalytic performance. Kinds of strategies have been developed to synthesize nanocatalysts with properties of low-cost, high-performance, and long lifetime. Pt-based catalyst is one of the most effective anodic materials for direct fuel cells (DFCs), especially towards ethylene glycol oxidation reaction (EGOR). Herein, we integrate the advantages of both composition and morphology to finally synthesize a series of PtBi chain-typed nanoflowers (NFs) serving as high-efficiency anode catalysts. The Pt 1 Bi 1 chain-typed NFs show much higher catalytic performances than Pt 1 Bi 2 , Pt 2 Bi 1 , and commercial Pt/C catalysts with the mass activity (1.17, 1.64, and 5.71 times higher, respectively) and retained mass activities (1.68, 3.26, and 13.1 times higher, respectively). Our present work opens a new way to promote the electrocatalytic activity and stability via synthesizing well-defined PtBi NFs with chain-typed structure. We also believe that the as-obtained PtBi NFs can be one of the candidates as promising anodic catalysts in DFCs. Image 1 • The PtBi chain-typed NFs have been synthesized by a facile one-pot method. • The PtBi chain-typed NFs provide abundant catalytic active sites. • The PtBi chain-typed NFs exhibits superior catalytic performance towards EGOR. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The fabrication of nanomaterials with tunable shape and size has attracted much attention in chemical and physical fields. It is particularly significant to study the effect of catalyst particle size on catalytic performance in the field of catalysis. At present, there are relatively few studies in this field, the main challenge lies in the difficulty of synthesizing catalysts with uniform size. If the particle size of a certain size is not uniform, it is meaningless to compare the catalytic performance with that of other catalysts for size effect. Herein, we successfully synthesized the monodisperse PdAg nanoparticles with three different sizes by changing the type of reducing agents. Among the three catalysts, the PdAg-S NPs (PdAg-Small nanoparticles) with an average size of 3.1 nm exhibited superior electrocatalytic performances of ethylene glycol and glycerol oxidation reactions, which were obviously better than others size PdAg NPs catalysts and commercial Pd/C catalyst. This work revealed the size effect of PdAg nanoparticles in the alcohols electrooxidation and provided a simple method in the design of different sizes of nanocrystals. [ABSTRACT FROM AUTHOR]

Bimetallic nanocatalysts with small particle size benefit from markedly enhanced electrocatalytic activity and stability during small molecule oxidation. Herein, we report a facile method to synthesize binary Pt-Ru nanoparticles dispersed on a carbon support at an optimum temperature. Because of its monodispersed nanostructure, synergistic effects were observed between Pt and Ru and the PtRu/C electrocatalysts showed remarkably enhanced electrocatalytic activity towards ethanol oxidation. The peak current density of the Pt 1 Ru 1 /C electrocatalyst is 3731 mA mg −1 , which is 9.3 times higher than that of commercial Pt/C (401 mA mg −1 ). Furthermore, the synthesized Pt 1 Ru 1 /C catalyst exhibited higher stability during ethanol oxidation in an alkaline medium and maintained a significantly higher current density after successive cyclic voltammograms (CVs) of 500 cycles than commercial Pt/C. Our work highlights the significance of the reaction temperature during electrocatalyst synthesis, leading to enhanced catalytic performance towards ethanol oxidation. The Pt 1 Ru 1 /C electrocatalyst has great potential for application in direct ethanol fuel cells. [ABSTRACT FROM AUTHOR]

A novel combined seed mediated and galvanic replacement method has been demonstrated to synthesize a new class of trimetallic PtAuAg nanocatalysts with highly open bowl-like nanocage structure. The newly-generated PtAuAg nanocages catalysts exhibit superior electrocatalytic performances towards ethylene glycol oxidation with the mass activity of 6357.1 mA mg −1 , 5.5 times higher than that of commercial Pt/C (1151.1 mA mg −1 ). This work demonstrates the first example of designing shape-controlled architectures of trimetallic bowl-like PtAuAg nanocages for liquid fuel electrooxidation. [ABSTRACT FROM AUTHOR]

Engineering binary Pd-based nanocatalysts with desirable morphology and structure has been of vital significance for the fabrication and modification of outstandingly excellent electrocatalysts. To embody the electrocatalysts with outstanding catalytic activity, it should be supposed to combine both the morphology advantages and the bifunctional effects. We herein report our significant advances in designing the unique binary PdNi hollow nanospheres with highly exposed active sites and tunable compositions. Owing to the bifunctional and electronic effect between Pd and Ni, as well as the unique hollow nanosphere structure, the unique PdNi hollow nanospheres exhibit outstandingly excellent catalytic activity towards ethylene glycol electrooxidation with the mass activity of 3152 mA mg −1 , which is 4.28-fold enhancement than that of the commercial Pd/C. The findings in this work may be favorable for greatly enhancing the catalytic activity by constructing the catalysts with maximized utilization of noble metals. [ABSTRACT FROM AUTHOR]

This article reports a rapid synthetic method for the preparation of dendritic platinum–lead bimetallic catalysts by using an oil bath for 5 min in the presence of hexadecyltrimethylammonium chloride (CTAC) and ascorbic acid (AA). CTAC acts as a shape-direction agent, and AA acts as a reducing agent during the reaction process. A series of physical techniques are used to characterize the morphology, structure and electronic properties of the dendritic Pt/Pb nanoparticles, indicating the Pt/Pb dendrites are porous, highly alloying, and self-supported nanostructures. Various electrochemical techniques were also investigated the catalytic performance of the Pt/Pb catalysts toward the ethanol electrooxidation reaction. Cyclic voltammetry and chronoamperometry indicated that the synthesized dendritic Pt/Pb nanoparticles possessed much higher electrocatalytic performance than bulk Pt catalyst. This study may inspire the engineering of dendritic bimetallic catalysts, which are expected to have great potential applications in fuel cells. [ABSTRACT FROM AUTHOR]

This work reports a simple method to design and synthesize PdNi nanospheres which supported on Vulcan XC-72R Carbon with NaBH 4 as reducing agent at ambient temperature and their superior electrocatalytic activity. The results of electrochemical measurements indicate that the PdNi nanospheres exhibit improved catalytic activity, excellent durability as well as higher long-term stability towards methanol oxidation reaction in comparison with commercial Pd/C catalysts. Furthermore, it is interpreted that the enhanced catalytic performance of the PdNi nanospheres is owing to the electronic effect between Pd and Ni and the spherical shape structure with rough surface. These findings highlighted the significance of precisely synthesizing the Pd/Ni nanospheres supported on Vulcan XC-72R Carbon and their emerging applications as electrocatalysts for direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

Abstract: High quality free-standing polyfluorene (PFe) films were synthesized electrochemically by direct anodic oxidation of fluorene in pure boron trifluoride diethyl etherate (BFEE) on stainless steel sheet. The oxidation potential of fluorene in this medium was measured to be only 1.1V versus SCE, which was much lower than that determined in acetonitrile+0.1molL−1 TBATFB. PFe films obtained from this medium showed good electrochemical behavior, good thermal stability with conductivity of 0.25Scm−1, indicating that BFEE is a better medium than acetonitrile for the electrosyntheses of PFe films. FTIR and 1H NMR spectral investigations indicated that the polymerization of fluorene occurred mainly at 2, 7 position. As-formed PFe films can be partly dissolved in acetone, acetonitrile, tetrahydrofuran, etc. [Copyright &y& Elsevier]