title: Reaction mechanism of methanol to formaldehyde over Fe- and FeO-modified graphene.
abstract: We employed periodic DFT calculations (PBE-D2) to investigate the catalytic conversion of methanol over graphene embedded with Fe and FeO. Two possible pathways of dehydrogenation to formaldehyde and dehydration to dimethyl ether (DME) over these catalysts were examined. Both processes are initiated with the activation of methanol over the catalytic center through O-H cleavage. As a result, a methoxo-containing intermediate is formed. Subsequently, H-transfer from the methoxy to the adjacent ligand leads to the formation of formaldehyde. Conversely, the activation of the second methanol over the intermediate gives DME and H2O. Over Fe/graphene, the dehydration process is kinetically and thermodynamically preferable. Unlike Fe/graphene, FeO/graphene is predicted to be an efficient catalyst for the dehydrogenation process. Oxidative dehydrogenation over FeO/graphene takes place through two steps with free energy barriers of 5.7 and 10.2 kcal mol(-1).
authors: Department of Chemistry and NANOTEC Center for Nanoscale Materials Design for Green Nanotechnology, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Center for Advanced Studies in Nanotechnology and Its Applications in Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900 (Thailand).
authors: Anawat
authors: A
authors: Thivasasith
authors: Jakkapan
authors: J
authors: Sirijaraensre
authors: Pipat
authors: P
authors: Khongpracha
authors: Chompunuch
authors: C
authors: Warakulwit
authors: Bavornpon
authors: B
authors: Jansang
authors: Jumras
authors: J
authors: Limtrakul
keywords: density functional calculations; graphene; iron; methanol; oxidation