Methanol decomposition on low index and stepped CeO2 surfaces from GGA+U

M.M. BRANDA; W. G. REIMERS

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 394 p. 509 - 518

0169-4332

GGA + U calculations have been carried out to study the complete methanol decomposition on the morestable Ceria surfaces, i.e. (111), (221), (331) and (110). These results have shown that the methanoladsorption is exothermic on oxidized as well as on the partially reduced surfaces though the adsorptionenergy is greater for the latest. The first dehydrogenation step of methanol is highly probable for all thestudied sites with activation barriers smaller than 0.2 eV. The first dehydrogenation reaction could alsooccur by breaking the C H methyl bond, but we found that this reaction is very unlikely. Reaction andactivation energies for the second dehydrogenation ? from methoxy to formaldehyde, are very similarfor perfect (111) and stepped surfaces but these activation barriers are not negligible, almost ten timesas many the first step barriers. Next, the formaldehyde decomposition to formyl and CO species onperfect CeO2(111) have an important energetic cost, therefore these reactions could occur only on steppedsurfaces.