Synergistic effects of ZrO2 crystallite islands and high dispersion of active Ni0 nanoparticles on CH4/CO2 reforming reaction

Abstract

A series of mesoporous 9NixZrO2/SBA-15 were prepared by coupled self-assembly and evaluated for CO2/CH4 reforming, which revealed that high activity and stability of 9Ni9ZrO2/SBA-15 correlated closely with the synergistic effects of ZrO2 crystallite islands and high dispersion of active Ni0 nanoparticles which promote adsorption of CO2 and facilitated high efficient conversion of residual CHx species. The XRD, O2-TPD, HAADF-Zr mapping and UV–vis DRS analysis verified the existence of stable ZrO2 crystallites and the formation of surface oxygen vacancies. The XPS and HRTEM images of 9NixZrO2/SBA-15 before and after CH4/CO2 reforming proclaimed the distribution of catalyst surface active species, synergistic action between CO2 and vacancies as well as formation character of CNTs. A catalytic mechanism of CH4/CO2 conversion into CO/H2 has been put forward. The allotropes of coke and physical properties of catalysts were systematically analyzed by TG/DTG, first derivative XAES, H2-TPR, N2-physisorption and FT-IR.