Effect of steam in CO2 reforming of CH4 over a Ni/CeO2-ZrO2-Al2O3 catalyst

CO2 reforming of CH4 was carried out with and without steam over a Ni/CeO2-ZrO2-Al2O3 catalyst. The catalytic performance, amount of carbon deposit and the EXAFS of the Ni K-edge of samples were measured. The results show that when the catalyst is used for CO2 reforming of CH4 without the addition of steam, the catalyst gradually deactivates, however, addition of a small amount of steam to the feed gas can significantly inhibits the deactivation, which is due to the great suppression of coke formation on the catalyst during the reaction. The EXAFS result shows that, maybe due to the penetration of more carbon atoms into the Ni lattice, the coordination number of the nearest Ni-Ni of the sample after the reaction without steam reduces more than that of samples after the reaction with a small amount of steam in the feed gas.