Recent Advances on Electro-Oxidation of Ethanol on Pt- and Pd-Based Catalysts: From Reaction Mechanisms to Catalytic Materials

Abstract

Abstract:The ethanol oxidation reaction (EOR) has drawn increasing interest in electrocatalysis and fuel cells by considering that ethanol as a biomass fuel has advantages of low toxicity, renewability, and a high theoretical energy density compared to methanol. Since EOR is a complex multiple-electron process involving various intermediates and products, the mechanistic investigation as well as the rational design of electrocatalysts are challenging yet essential for the desired complete oxidation to CO2. This mini review is aimed at presenting an overview of the advances in the study of reaction mechanisms and electrocatalytic materials for EOR over the past two decades with a focus on Pt-and Pd-based catalysts. We start with discussion on the mechanistic understanding of EOR on Pt and Pd surfaces using selected publications as examples. Consensuses from the mechanistic studies are that sufficient active surface sites to facilitate the cleavage of the C-C bond and the adsorption of water or its residue are critical for obtaining a higher electro-oxidation activity. We then show how this understanding has been applied to achieve improved performance on various Pt-and Pd-based catalysts through optimizing electronic and bifunctional effects, as well as by tuning their surface composition and structure. Finally we point out the remaining key problems in the development of anode electrocatalysts for EOR. OPEN ACCESSCatalysts 2015, 5 1508

Study of PtPd Bimetallic Nanoparticles for Fuel Cell Applications

“…Pt is the most used catalytic metal in the fuel cells, mainly in direct ethanol fuel cells 10 ; however one of the problems of the Pt catalyst is the poisoning by carbon monoxide 11 . A solution to enhancement the electrocatalytic properties is to mix the Pt with other elements or deposited on different supports 12 .…”

The Performance of Electron-Mediator Modified Activated Carbon as Anode for Direct Glucose Alkaline Fuel Cell

“…In recent years, with the rapid development of global industrialization, environmental problems caused by fossil fuel combustion are becoming more and more serious [1][2][3][4][5]. As possible alternatives of fossil fuel, biomass resources-one of the renewable energy sources-has attracted much attention [6][7][8][9][10].…”

Enhancement of Ethanol Oxidation Reaction on Pt (PtSn)-Activated Nickel Foam Through In situ Formation of Nickel Oxy-Hydroxide Layer

“…Pathway I [7]: CH 3 [4,[9][10][11] enabled application of non-noble and highly corrosion-resistant metals, such as different forms of nickel [12,13]. Thus, employment of highly modifiable, large specific surface area nickel foam could be a key point in the development of low noble metal level and highly electroactive catalyst composites for alkaline direct ethanol fuel cells [14][15][16].…”

“…Ethanol oxidation reaction (EOR) is a complex anodic process, which involves dissociation of preadsorbed ethanol molecules to produce surface-adsorbed carbon monoxide (CO ad ) species and further oxidation of C 2 H 5 OH to form (apart from numerous intermediates and by-products) two major chemicals, namely acetaldehyde and acetic acid (Pathway I: 4e − ). In fact, most of these products might become adsorbed on the catalyst surface, and thus, quantitative cleavage of the C-C bond (in order to finally generate CO 2 Pathway II: 12e − ) in an ethanol molecule constitutes a key technical problem [1][2][3][4][5][6][7][8].…”