Exceptional low-temperature activity of a perovskite-type AlCeO3 solid solution-supported Ni-based nanocatalyst towards CO2 methanation

摘要

Currently, the development of high-performance and stable non-noble metal catalysts for low-temperature CO2 methanation is quite challenging for practical industrial applications in terms of highly efficient and renewable energy storage and conversion. In this work, highly dispersed Ni nanoparticles over a perovskite-type AlCeO3 solid-solution support as catalysts for exceptional low-temperature CO2 methanation were synthesized via an innovative single-source Ni-Al-Ce layered double hydroxide (LDH) precursor route. It was demonstrated that the as-fabricated Ni-based catalyst with a Ce/(Ce + Al) molar ratio of 0.2 displayed superior low-temperature catalytic activity for CO2 methanation compared to the Ce-free Ni catalyst and Ni/CeO2 and Ni/Al2O3 catalysts obtained via the impregnation method for comparison, with a high CO2 conversion of 83.2% at only 200 degrees C and a high CO2 turnover frequency value of 18.2 h(-1) achieved at a low reaction temperature of 175 degrees C. This remarkable low-temperature activity of the catalyst for CO2 methanation outperforms all other supported Ni catalysts reported thus far. It was verified that the favorable Ce3+ sites in the perovskite-type AlCeO3 solid solution contribute to the enhanced medium-strength surface basicity, which is beneficial for CO2 adsorption and the formation of formate intermediate species, thus greatly accelerating the transformation of formate intermediates to the target methane product. Furthermore, for the Ni/AlCe-0.2 catalyst, no deactivation could be observed, indicating the good stability and reusability of the Ce-containing Ni-based catalysts. The present findings provide a new stable and high-performance non-noble metal-based catalyst by integrating Ni nanoparticles with perovskite-type AlCeO3 solid-solution support for exceptional low-temperature CO2 methanation.