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

Methane synthesis from CO 2 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 CH 4 from CO 2 at atmospheric pressure and 325°C. The reactor was steadily operated for 1000 hours. The results showed that both the CO 2 conversion and the CH 4 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 CO 2 was converted to CH 4 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 CO 2 -derived methane at high temperatures. • Sintering-resistance flat-tube Ni-YSZ reactor for CO 2 methanation was designed. • The reactor underwent 1000 hrs and remained stable at a temperature of 325 °C. • The reactor converted over 88 % of CO 2 and selected over 99.9 % of CH 4 at atmospheric pressure atm.