Decomposition of acetic acid monomer, acetic acid dimer, and acetic anhydride on Ni(111)

The decomposition of acetic acid monomer, acetic acid dimer, and acetic anhydride on Ni(111) were examined by TPD and AES. The monomer decomposed by dehydrogenation to adsorbed acetate; the acetate subsequently decomposed to CO₂, H₂, and adsorbed carbon and oxygen. The dimer decomposed by dehydration to adsorbed acetate, adsorbed methyl, and adsorbed CO. The adsorbed methyl group decomposed to H₂ and adsorbed carbon; the acetate decomposed by the same route as for the monomer though the decomposition kinetics were influenced by the adsorbed CO. Acetic anhydride decomposed at 300 K, with adsorbed acetate, CO, and some methyl groups remaining on the surface. These adsorbates then decomposed to the same products observed for acetic acid dimer. The results show that acetic acid derivatives react by the same mechanism as formic acid derivatives.