Del Colle V, Berná A, Tremiliosi-Filho G, Herrero E, Feliu J M
Universidade Estadual de Alagoas, Av. Governador Luiz Cavalcanti S/N, 57312-000, Arapiraca and Centro Federal de Educação Tecnológica de Alagoas-CEFET-AL, Rua Barão de Atalaia, Poço, Al, Brazil.
Phys Chem Chem Phys. 2008 Jul 7;10(25):3766-73. doi: 10.1039/b802683a. Epub 2008 May 22.
Oxidation of ethanol on ruthenium-modified Pt(775) and Pt(332) stepped electrodes has been studied using electrochemical and FTIR techniques. It has been found that the oxidation of ethanol on these electrodes takes place preferentially on the step sites yielding CO(2) as the major final product. The cleavage of the C-C bond, which is the required step to yield CO(2), occurs only on this type of site. The presence of low ruthenium coverages on the step sites promotes the complete oxidation of ethanol since it facilitates the oxidation of CO formed on the step from the cleavage of the C-C bond. However, high ruthenium coverages have an important inhibiting effect since the adatoms block the step sites, which are required for the cleavage of the C-C bond. Under these conditions, the oxidation current diminishes and the major product in the oxidation process is acetic acid, which is the product formed preferentially on the (111) terrace sites.
采用电化学和傅里叶变换红外光谱（FTIR）技术研究了乙醇在钌修饰的Pt(775)和Pt(332)阶梯电极上的氧化过程。研究发现，乙醇在这些电极上的氧化优先发生在阶梯位点，主要最终产物为CO₂。产生CO₂所需的C-C键断裂仅发生在这类位点上。阶梯位点上低钌覆盖量的存在促进了乙醇的完全氧化，因为它有助于氧化阶梯上因C-C键断裂而形成的CO。然而，高钌覆盖量具有重要的抑制作用，因为吸附原子会阻塞C-C键断裂所需的阶梯位点。在这些条件下，氧化电流减小，氧化过程中的主要产物是乙酸，乙酸是优先在(111)平台位点上形成的产物。
