title: Mechanistic insight into oxide-promoted palladium catalysts for the electro-oxidation of ethanol.
abstract: Recent advancements in the development of alternatives to proton exchange membrane fuel cells utilizing less-expensive catalysts and renewable liquid fuels, such as alcohols, has been observed for alkaline fuel cell systems. Alcohol fuels present the advantage of not facing the challenge of storage and transportation encountered with hydrogen fuel. Oxidation of alcohols has been improved by the promotion of alloyed or secondary phases. Nevertheless, currently, there is no experimental understanding of the difference between an intrinsic and a synergistic promotion effect in high-pH environments. This report shows evidence of different types of promotion effects on palladium electrocatalysts obtained from the presence of an oxide phase for the oxidation of ethanol. The correlation of mechanistic in situ IR spectroscopic studies with electrochemical voltammetry studies on two similar electrocatalytic systems allow the role of either an alloyed or a secondary phase on the mechanism of oxidation of ethanol to be elucidated. Evidence is presented for the difference between an intrinsic effect obtained from an alloyed system and a synergistic effect produced by the presence of an oxide phase.
authors.affiliation: Center for Emerging Energy Technologies, The University of New Mexico, 1 University of New Mexico-MSC01 1120, Albuquerque, NM 87131 (USA); Present Address: Materials Physics and Applications, Los Alamos National Laboratory, Los Alamos, NM 87545 (USA).
authors.forename: Ulises
authors.initials: U
authors.lastname: Martinez
authors.forename: Alexey
authors.initials: A
authors.lastname: Serov
authors.forename: Monica
authors.initials: M
authors.lastname: Padilla
authors.forename: Plamen
authors.initials: P
authors.lastname: Atanassov
mesh_terms: D002384:Catalysis; D004563:Electrochemistry; D000431:Ethanol / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D017971:Tin Compounds; D000431:Ethanol; D010165:Palladium; C045358:stannic oxide
keywords: IR spectroscopy; electrochemistry; ethanol; fuel cells; palladium