A sintered Ni-YSZ catalytic reactor for highly efficient synthesis of green CH4

Methane synthesis from CO2 is an important process for transforming and storing renewable electrical energy, and one of the main issues facing methanation catalysts is stability. Herein, a plate-and-tube structured porous metal-ceramic Ni-YSZ reactor with high-temperature sintering was designed to produce CH4 from CO2 at atmospheric pressure and 325°C. The reactor was steadily operated for 1000 hours. The results showed that both the CO2 conversion and the CH4 selectivity continuously stayed over 90 % and 99.9 %, respectively. The results of in situ infrared and in situ programmed warming characterizations demonstrated that the hydrogenation of oxygen vacancies on the surface of Ni-O-Zr was the main pathway by which CO2 was converted to CH4 in this reactor. Moreover, the strongly basic adsorbed HCOO* and CO* intermediates facilitated further hydrogenation. This reactor structure decreases the reduction in reaction activity associated with catalyst sintering, coalescence, and carbon accumulation. Moreover, it provides a novel approach to reactor design for the stable operation of CO2-derived methane at high temperatures.