Hierarchically Porous Network‐Like Ni/Co 3 O 4 : Noble Metal‐Free Catalysts for Carbon Dioxide Methanation

The impasse always present regarding catalysts for energy conversion reactions is that noble metals with promising activity are limited by their high price and scarcity, whereas base metals with a lower price show moderate activity performance. Herein, a purely transition metal‐based, Ni‐promoted 3D draped porous Co 3 O 4 (Ni/3DDP‐Co 3 O 4 ) catalyst is demonstrated to be highly effective for CO 2 methanation, achieving 100% CO 2 conversion and CH 4 selectivity at 250 °C and a space velocity of 48 000 mL (g h) −1 . Dispersing Ni nanodeposits on the large surface of the 3DDP‐Co 3 O 4 promotes a 2.6 times increase in reaction rate and a 20% drop in apparent activation energy relative to 3DDP‐Co 3 O 4 . An abundance of surface oxygen vacancies extrinsically forms on the Ni/3DDP‐Co 3 O 4 by both Co–Ni charge‐compensating mechanisms and hydrogen treatment, in conjunction with the low‐temperature reducibility, high surface area, and strong Co–Ni interaction effect, enabling the enhanced catalytic performance for CO 2 methanation.