NUK - logo
E-resources
Full text
Peer reviewed
  • Combined experimental and d...
    Lim, Seoyeon; Choi, Jae-Wook; Suh, Dong Jin; Song, Kwang Ho; Ham, Hyung Chul; Ha, Jeong-Myeong

    Journal of catalysis, 07/2019, Volume: 375
    Journal Article

    Display omitted •Descriptors for oxidative coupling of methane were investigated.•Density functional theory described the actual catalysis results.•Optimum methyl radical adsorption energy was found for good catalysts.•The roles of surface oxygen species were revealed by surface characterizations. 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 CH 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.