A detailed theoretical treatment of the partial oxidation of methane to syngas on transition and coinage metal (M) catalysts (M = Ni, Pd, Pt, Cu)

Chak Tong AU, Meng Sheng Liao*, Ching Fai Ng

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

81 Citations (Scopus)

Abstract

This paper presents a detailed theoretical treatment of the partial oxidation of methane to syngas (OMS) on transition and coinage metal (M) catalysts (M = Ni, Pd, Pt, Cu). The adsorption energies for a number of intermediates in the dissociation of methane on the metals were calculated using medium sized cluster models of 7-13 atoms. Reaction energies for methane dissociation, syngas formation, and byproduct generation were determined. The activation energies were estimated by means of the analytic BOC-MP formula. On the basis of these results, several significant aspects involved in the OMS on the metal catalysts have been elucidated. (1) The total dissociation energy (De) for the complete dissociation of methane to give surface carbon and hydrogen (CH4,s → Cs + 4Hs) can be regarded as a measure for the activity of the metal in methane dissociation. The order of the calculated De's is consistent with the order of methane conversions over the metals. (2) In the presence of coadsorbed oxygen, oxygen at metal on-top site increases the adsorption energy of H and promotes methane dehydrogenation. Oxygen at the hollow site may or may not promote methane dehydrogenation, depending on the metal. (3) For the possible reactions for the coupling of the intermediates on the metal surfaces, CHx,s + CHx,s → C2H2x,s, the trend in the calculated combination energies is in agreement with experimental observation.

Original languageEnglish
Pages (from-to)3959-3969
Number of pages11
JournalJournal of Physical Chemistry A
Volume102
Issue number22
DOIs
Publication statusPublished - 28 May 1998

Scopus Subject Areas

  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'A detailed theoretical treatment of the partial oxidation of methane to syngas on transition and coinage metal (M) catalysts (M = Ni, Pd, Pt, Cu)'. Together they form a unique fingerprint.

Cite this