Eu3+ doping-promoted Ni-CeO2 interaction for efficient low-temperature CO2 methanation

CO 2 methanation is gaining renewed attention due to the emerging application needs such as the power-to-gas concept and long-term space exploration missions. Maximizing the amounts of interfacial sites generally regarded as the efficient active sites is considered to be one of the most direct means to enhance catalytic activity but few breakthroughs have been made. Here, Eu 3+ is introduced to Ni/CeO 2 to promote the Ni-CeO 2 interaction, resulting in a remarkable low-temperature CO 2 methanation activity. Structural characterization indicates that the Ni/CeEu(9:1) catalyst achieves higher Ni dispersion compared to Ni/CeO 2 , which consequently generates more interfacial sites. More interfacial sites enhance the proportions of bidentate carbonates closer to interfacial sites as a faster hydrogenated species during the catalytic process, leading to enhanced low-temperature CO 2 methanation activity over the Ni/CeEu(9:1) catalyst. This work provides a chemical strategy to enhance the amounts of active sites and bring insights into the origin of enhanced catalytic performance. • Ni/CeEu(9:1) completely converts CO 2 to CH 4 in a H 2 -rich stream at 210 °C. • Eu 3+ doping into Ni/CeO 2 promotes Ni dispersion and interfacial sites generation. • Interfacial sites facilitate the formation of faster hydrogenated intermediates. • More faster hydrogenated species lead to better CO 2 methanation performance.