Studies on catalysis in partial oxidation of methane to syngas .1. Performance and characterization of Ni-based catalysts
- 化学化工－已发表论文 
Highly active and selective Ni-based catalysts for partial oxidation of methane (POM) to syngas (CO/H-2) have been studied and developed. Spectroscopic characterization by XRD, XPS, EPRI Ptc. demonstrated that under the POM reaction conditions, the Ni-components of the catalysts investigated were reduced and enriched on the surface to form metallic Ni-o-phase. A comparative study of the first series of transition-metals showed that only Ni and Co have a high POM activity and selectivity, whereas the others (including Mn, Fe, Cu, etc.) give mainly complete combustion products, CO2 and H2O. The results favor the following viewpoints: the POM activity is related with the rapidly changeable valence transition-metal sites, M(o)/M(2+) (e.g. Ni-o/Ni2+), on the surface of the functioning catalysts; the transition-metal sites in zero-valence state seem to be responsible for the activation and dehydrogenation of methane by homolytic splitting of its C-H bonds on these sites, and the nature of rapidly changeable valence of the active sties is requisite for activation and rapid conversion of dioxygen.