Insight into carbon formation from acetic acid decomposition over Pd(100) via density functional theory calculations

Abstract

The mechanism of carbon deposition in acetic acid/palladium system is of great research significance in the catalytic field. In order to illustrate the plausible carbon formation routes, a systematic survey on the stepwise decomposition from adsorbed acetic acid to atomic carbon on Pd(100) was conducted via density functional theory calculations. A complex reaction network including OH bond scission reaction and various CH and CC bond scission reactions was built and the relevant structural and energetic properties were calculated. The results show that OH bond breaking is very possible for CH3COOH, that CC bond breaking is always more favorable than CH bond breaking for CHxCOO (x = 1–3), and the dehydrogenation of CHx (x = 1–3) is more likely to proceed than most of other reactions. The most possible pathway for the formation of carbon monomer was proposed based on the analysis of the reaction network and it features the decarbonation of CH3COO to CH3 as the rate-limiting step.