Combined experimental and density functional theory (DFT) studies on the catalyst design for the oxidative coupling of methane

Seoyeon Lim, Jae Wook Choi, Dong Jin Suh, Kwang Ho Song, Hyung Chul Ham, Jeong Myeong Ha

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2 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)478-492
Number of pages15
JournalJournal of Catalysis
Volume375
DOIs
Publication statusPublished - 2019 Jul 1

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Keywords

  • Density functional theory
  • Methyl radical adsorption
  • Oxidative coupling of methane
  • Perovskite

ASJC Scopus subject areas

  • Catalysis
  • Physical and Theoretical Chemistry

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