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

Abstract

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 °C and a high CO₂ turnover frequency value of 18.2 h⁻¹ achieved at a low reaction temperature of 175 °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.