Low-temperature conversion of CaO-captured CO2 to CH4 over a greenly prepared Ni/CaO/Al2O3 composite under static pressure conditions

Directly converting metal oxide-adsorbed CO2 to CH4 at low temperatures is a more energy-saving method for achieving carbon capture and utilization. In this study, an Al2O3-supported Ni/CaO composite was greenly prepared by a mechanochemical method. It is found that CO2 capture and selective methanation can be realized over the Ni/CaO/Al2O3 composite at as low as 200 °C under static pressure conditions. The methane yields over the 10Ni/10CaO/γ-Al2O3 composite reach 70.05 and 388.5 μmol CH4 per g at 200 and 350 °C with approximately 100% selectivity to CH4. The experimental results show that the reaction time and temperature obviously affect the methanation yield over the Ni/CaO/Al2O3 composite. This work provides a facile energy-saving strategy for converting CO2 to CH4 at low temperatures.