Ni nanoparticles dispersed on oxygen vacancies-rich CeO2 nanoplates for enhanced low-temperature CO2 methanation performance

Developing efficient catalysts with superior low-temperature catalytic performance is highly promising yet challenging for CO2 methanation. Here we synthesized a nanoplate-shaped CeO2, which was rich in oxygen vacancies, as the carrier to disperse the nickel nanoparticles. The resultant catalyst (Ni/CeO2-P) showed remarkable low-temperature CO2 methanation performance with a CO2 conversion of high than 84% and 100% CH4 selectivity at a low temperature of 300 degrees C. A 100 h-on-stream test at 300 degrees C demonstrated the excellent stability of Ni/CeO2-P. Even when the WHSV rose as high as 30000 mL g(-1) h(-1), the Ni/CeO2-P catalyst still possessed a maximum CO2 conversion of approximately 79%. The surface characterization demonstrated that the abundant oxygen vacancies on the CeO2 nanoplates led to more amounts of NiO-CeO2 structures formed, which resulted in a stronger interaction between Ni metal and CeO2 support. This stronger NiO-CeO2 interaction was proved extraordinary in promoting the reaction performance as compared with metallic Ni. Also, by the in-situ DRIFTS technology, the reaction intermediates and possible reaction pathway were raised for CO2 methanation.