Carbon dioxide reforming of methane reaction catalyzed by stable nickel copper catalysts

Abstract

A long-term stable Cu/Ni/SiO 2 catalyst for carbon dioxide reforming of methane to produce synthesis gas at 800 °C was developed. The stability of the Cu/Ni catalysts depends on the reaction temperature and Cu/Ni ratio. Temperature programmed oxidation and temperature programmed reaction with CO 2 were applied to Ni and Cu/Ni catalysts to study the effect of Cu on Ni catalyst. The stability can not be fully explained by the ensemble effect of the Cu on Ni metal that may inhibit the carbon formation rate on Ni catalyst. Copper may stabilize the structure of the active site on Ni surface for methane cracking reaction, preventing the deactivation of the Ni catalyst caused by sintering or by loss of nickel crystallites. The addition of Cu into Ni catalyst system can fine-tune the catalytic activity so that the CH 4 cracking and removal of coke by CO 2 is balanced and prevent inactive coke accumulation on Ni particle. Thus encapsulated carbon layer does not formed on supported Cu/Ni giving the catalyst a stable activity.