Enhancing low-temperature CO2 methanation performance by selectively covering Ni with CeO2 to form Ni-O-Ce interface active sites

The methanation of CO2 2 is crucial for resource utilization, however, achieving excellent CO2 2 methanation performance with Ni-based catalysts at low temperatures remains highly challenging. In this study, a highperformance 10Ni-0.1Ce/Al catalyst was synthesized using a simple and efficient one-pot combustion method. Unlike other catalysts with the same components, this catalyst exhibits a unique feature where a small amount of the CeO2 2 promoter is dispersed on the support, while the majority selectively binds to and coats the Ni nano- particles. This distinctive structure allows it to achieve approximately 80 % CO2 2 conversion and 99.9 % CH4 4 selectivity under conditions of 260 degrees C, 0.1 MPa, and a GHSV of 48,000 mL & sdot;g- & sdot; g- 1 & sdot;h-1. & sdot; h- 1 . The high catalytic performance is attributed to the unique structure of Ni nanoparticles and CeO2, 2 , which promotes the formation of numerous Ni-O-Ce interface active sites. These Ni-O-Ce interfaces enhance the reducibility and increase the content of weak basic sites in the catalyst. The combination of in-situ DRIFTS and TPSR reveals that the decomposition of bridged HCOO- - to *CO is the rate-determining step. The presence of Ni-O-Ce interface active sites in the 10Ni-0.1Ce/Al catalyst facilitates the generation of abundant bridged HCOO- - intermediates with higher activity than the 10Ni/Al catalyst, leading to a substantial enhancement in catalytic performance.