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.

Automated summary

Efficient catalysts for CO2 methanation at low temperature are highly promising yet challenging to develop. This study successfully synthesized a Ni/CeO2-P catalyst with nanoplate-shaped CeO2 as the carrier and dispersed nickel nanoparticles, showing remarkable performance at 300 degrees C with high CO2 conversion rate and 100% CH4 selectivity. The catalyst also demonstrated excellent stability even under high WHSV, showcasing the potential for practical applications. Characterization revealed the crucial role of abundant oxygen vacancies in promoting the interaction between Ni metal and CeO2 support for enhanced catalytic performance. Additionally, in-situ DRIFTS technology provided insights into reaction intermediates and possible pathways for CO2 methanation.