Effect of oxygen addition on catalytic performance of Ni/SiO2·MgO toward carbon dioxide reforming of methane under periodic operation

This work investigates the catalytic performance of an industrial steam reforming Ni/SiO2·MgO catalyst toward dry reforming of CH4 under periodic operation. The effects of cracking/regeneration temperatures and O2 addition during regeneration on the catalyst stability and activity were determined and various characterizations i.e. BET, SEM, XRD, and TPO were employed to relate the catalyst performance with its physical properties. It was found that, without O2 addition, the catalyst showed good stability at 650 °C but observed high deactivation at 750 °C due to the formation of encapsulating carbon. The addition of O2 along with CO2 can eliminate all deactivation at 750 °C and no significant loss of catalyst activity was observed for at least 12 cracking/regeneration cycles. The optimal performance for periodic operation was found at the condition with 5 min of the cracking step followed by 5 min of the regeneration step at 750 °C with CO2/O2 ratio of 7/3.