The Influence of Surface Structure on Selectivity in the Ethanol Electro-oxidation Reaction on Platinum

Product selectivity is an important issue in the ethanol electrooxidation reaction, in view of the efficiency and the sustainability of the reaction. In this letter, we have studied the effect of the surface structure on the selectivity by online electrochemical mass spectrometry (OLEMS) on a series of platinum single-crystal electrodes in perchloric and sulfuric acid solutions. By monitoring mass fractions of CO(2) and acetaldehyde, it is shown that (110) steps do not effect the product distribution in a perchloric acid solution. On the other hand, in a sulfuric acid solution, (110) steps strongly favor the formation of CO(2). The results emphasize the importance of considering all structure sensitive interactions, including those of specifically adsorbing anions, in the ethanol oxidation reaction when considering the structure-selectivity relationship.