TY - JOUR
T1 - Combined experimental and density functional theory (DFT) studies on the catalyst design for the oxidative coupling of methane
AU - Lim, Seoyeon
AU - Choi, Jae Wook
AU - Suh, Dong Jin
AU - Song, Kwang Ho
AU - Ham, Hyung Chul
AU - Ha, Jeong Myeong
N1 - Funding Information:
This work was supported by C1 Gas Refinery Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and and ICT ( 2015M3D3A1A01064900 ).
PY - 2019/7
Y1 - 2019/7
N2 - Catalytic descriptors were studied to design optimum catalysts for the oxidative coupling of methane (OCM) by combining density functional theory (DFT) calculations and actual reaction experiments. SrTiO3 perovskite catalysts, selected for OCM, were modified using metal dopants, and their electronic structures were calculated using the DFT method. The CH3 adsorption energy Eads(CH3) and the oxygen vacancy formation energy Ef(vac) exhibited volcano-type correlations with the C2+ selectivity and O2-consumption for the formation of COx, respectively. The optimum catalytic activity, represented by the C2+ selectivity, was obtained for Eads(CH3) = −2.0 to −1.5 eV, indicating that overly strong adsorption of methyl radicals (or easily dissociated C[sbnd]H bonds of methane) and relatively insufficient oxygen supplementation to the catalyst surface improve deep oxidation to CO and CO2. Praseodymium (Pr)- and neodymium (Nd)-doped SrTiO3 catalysts confirm the DFT-predicted optimum electronic structure of the OCM catalysts.
AB - Catalytic descriptors were studied to design optimum catalysts for the oxidative coupling of methane (OCM) by combining density functional theory (DFT) calculations and actual reaction experiments. SrTiO3 perovskite catalysts, selected for OCM, were modified using metal dopants, and their electronic structures were calculated using the DFT method. The CH3 adsorption energy Eads(CH3) and the oxygen vacancy formation energy Ef(vac) exhibited volcano-type correlations with the C2+ selectivity and O2-consumption for the formation of COx, respectively. The optimum catalytic activity, represented by the C2+ selectivity, was obtained for Eads(CH3) = −2.0 to −1.5 eV, indicating that overly strong adsorption of methyl radicals (or easily dissociated C[sbnd]H bonds of methane) and relatively insufficient oxygen supplementation to the catalyst surface improve deep oxidation to CO and CO2. Praseodymium (Pr)- and neodymium (Nd)-doped SrTiO3 catalysts confirm the DFT-predicted optimum electronic structure of the OCM catalysts.
KW - Density functional theory
KW - Methyl radical adsorption
KW - Oxidative coupling of methane
KW - Perovskite
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U2 - 10.1016/j.jcat.2019.04.008
DO - 10.1016/j.jcat.2019.04.008
M3 - Article
AN - SCOPUS:85068550811
VL - 375
SP - 478
EP - 492
JO - Journal of Catalysis
JF - Journal of Catalysis
SN - 0021-9517
ER -