Open AccessMixed Anion Control of the Partial Oxidation of Methane to Methanol on the β-PtO2Surface
Author(s) -
Yuta Tsuji,
Keita Kurino,
Kazunari Yoshizawa
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c01476
Subject(s) - chemistry , catalysis , bond cleavage , methanol , bond energy , atom (system on chip) , activation energy , methane , bond order , ion , platinum , computational chemistry , crystallography , bond length , molecule , organic chemistry , crystal structure , computer science , embedded system
Although the C-H bond of methane is very strong, it can be easily dissociated on the (110) surface of β-PtO 2 . This is because a very stable Pt-C bond is formed between the coordinatively unsaturated Pt atom and CH 3 on the surface. Owing to the stable nature of the Pt-C bond, CH 3 is strongly bound to the surface. When it comes to methanol synthesis from methane, the Pt-C bond has to be cleaved to form a C-O bond during the reaction process. However, this is unlikely to occur on the β-PtO 2 surface: The activation energy of the process is calculated to be so large as 47.9 kcal/mol. If the surface can be modified in such a way that the ability for the C-H bond activation is maintained but the Pt-C bond is weakened, a catalyst combining the functions of C-H bond cleavage and C-O bond formation can be created. For this purpose, analyzing the orbital interactions on the surface is found to be very useful, resulting in a prediction that the Pt-C bond can be weakened by replacing the O atom trans to the C atom with a N atom. This would be a sort of process to make β-PtO 2 a mixed anion compound. Density functional theory simulations of catalytic reactions on the β-PtO 2 surface show that the activation energy of the rate-limiting step of methanol synthesis can be reduced to 27.7 kcal/mol by doping the surface with N.