Methanol oxidation, electrocatalysts

Role of Anode Electrocatalysts—Methanol Oxidation Reaction (MOR)... 

In addition to these different types of alloys, some studies were also devoted to alternatives to platinum as electrocatalysts. Unfortunately, it is clear that even if some catalytic activities were observed, they are far from those obtained with platinum. Nickel tungsten carbides were investigated, but the electrocatalytic activity recorded for methanol oxidation was very low. Tungsten carbide was also considered as a possible alternative owing to its ability to catalyze the electrooxidation of hydrogen. However, it had no activity for the oxidation of methanol and recently some groups showed that a codeposit of Pt and WO3 led to an enhancement of the activity of platinum. ... 

Leger, J.-M., Mechanistic apects of methanol oxidation on platinum based electrocatalysts, J. Appl. Electrochem., 31, 767 (2001). 

Methanol tolerance is a very important property of Pd-M alloys. In particular, methanol tolerance was demonstrated for PdsFe/C and for Pd-Co based alloys [Mustain et al., 2007 Raghuveer et al., 2005 Shao et al., 2006c Zhang L et al., 2007]. The high ORR activity in the presence of a high concentration of methanol indicates that the Pd-Co and Pd-Fe electrocatalysts are not active for methanol oxidation. 

Dubau L, Hahn P, Coutanceau C, Leger JM, Lamy C. 2003b. On the stracture effects of bime-talhc FTRu electrocatalysts towards methanol oxidation. J Electroanal Chem 554/555 407-415. 

Radmilovic V, Gasteiger HA, Ross PN. 1995. Structure and chemical composition of a supported Pt-Ru electrocatalyst for methanol oxidation. J Catal 154 98-106. 

Wang H, Wingender Ch, Baltmschat H, Lopez M, Reetz MT. 2001b. Methanol oxidation on Pt, PtRu, and colloidal Pt electrocatalysts A DEMS study of product formation. J Electroanal Chem 509 163-169. 

Mukerjee, S. and Urian, R.C., Bifunctionality in Pt alloy nanocluster electrocatalysts for enhanced methanol oxidation and CO tolerance in PEM fuel cells electrochemical and in situ synchrotron spectroscopy, Electrochim. Acta, 47, 3219, 2002. 

Santhosh, P., A. Gopalan, and K.-P. Lee, Gold nanoparticles dispersed polyaniline grafted muttiwall carbon nanotubes as newer electrocatalysts Preparation and performances for methanol oxidation. Journal of Catalysis, 2006. 238(1) p. 177-185. 

The difSculty of electrochemical oxidation of methanol is due to the lack of a good electrocatalyst. It is not overstated, therefore, that ultimate goal of all studies on methanol oxidation is to find the electrocataljrst. 

Overcoming this poisoning effect is a m gor challenge in a study in electrocatalyst for methanol oxidation. 

In the case of ethanol, Pd-based electrocatalysts seem to be slightly superior to Pt-based catalysts for electro-oxidation in alkaline medium [87], whereas methanol oxidation is less activated. Shen and Xu studied the activity of Pd/C promoted with nanocrystalline oxide electrocatalysts (Ce02, C03O4, Mn304 and nickel oxides) in the electro-oxidation of methanol, ethanol, glycerol and EG in alkaline media [88]. They found that such electrocatalysts were superior to Pt-based electrocatalysts in terms of activity and poison tolerance, particularly a Pd-NiO/C electrocatalyst, which led to a negative shift of the onset potential ofthe oxidation of ethanol by ca 300 mV compared... 

G. Goekagac, J.-M. Leger, F. Hahn, C. Lamy, Carbon Supported Pt, Pt/W and Pt/Mo Electrocatalysts for Methanol Oxidation Electrochemical and IR Spectroscopic Characterisation, Electrochemical Society Proceedings, 2001, p. 174. 

This chapter presents the design and application of a two-stage combinatorial and high-throughput screening electrochemical workflow for the development of new fuel cell electrocatalysts. First, a brief description of combinatorial methodologies in electrocatalysis is presented. Then, the primary and secondary electrochemical workflows are described in detail. Finally, a case study on ternary methanol oxidation catalysts for DMFC anodes illustrates the application of the workflow to fuel cell research. 

Research on the direct conversion of chemical energy to electricity via fuel cells has received considerable attention in the past decades. Fuel cells are indeed attractive alternatives to combustion engines for electrical power generation in transportation applications and also as promising future power sources, especially for mobile and portable applications. Thus, the search for excellent electrocatalysts for the electro-catalytic oxygen reduction and methanol oxidation reactions, which are the two important cathodic and anodic reactions in fuel cells, is intensively pursued by scientists... 

Pt-based electrocatalysts are usually employed in proton exchange membrane fuel cells (PEMFC) and direct methanol fuel cells (DMSC). In direct-methanol fuel cells (DMFCs), aqueous methanol is electro-oxidized to produce COj and electrical current. To achieve enhanced DMFC performance, it is important to develop electrocatalysts with higher activity for methanol oxidation. Pt-based catalysts are currently favored for methanol electro-oxidation. In particular, Pt-Ru catalysts, which gave the best results, seem to be very promising catalysts for this application. Indeed, since Pt activates the C-H bounds of methanol (producing a Pt-CO and other surface species which induces platinum poisoning), an oxophilic metal, such as Ru, associated to platinum activates water to accelerate oxidation of surface-adsorbed CO to... 

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