Abstract
Catalytic ethanol oxidation reaction (EOR) takes place via many elementary reactions, such as dehydrogenation, C-C bond cleavage, and oxidation of C1 species. Recent studies indicate that hydrogen transfer reaction between intermediate species may need to be included in the reaction network to fully understand the transient kinetics of EOR catalysis. Furthermore, it is important to examine the requirement of the minimum elementary reactions (MERs) in the complex EOR network to calculate the apparent reaction rate and product selectivity. In this work, we performed density functional theory calculations to study the effects of catalyst using Ir(100) and one or two water molecules on the tautomerization reaction between vinyl alcohol (VA) and acetaldehyde (AA). The DFT results show that Ir(100) does not lower the VA-AA tautomerization barrier significantly, however, the presence of water molecules lowers the VA-AA tautomerization barrier considerably. This illustrates that VV-AA tautomerization during EOR occurs with water molecules serving as catalysts.