Electronic regulation of metallic nanoparticles in cages enables thermodynamic-limit CO2-to-CH4 conversion

Abstract

CO₂ hydrogenation offers a green and sustainable solution to produce carbon-neutral fuels for mitigating the global energy issue. However, the highly selective and stable formation of methane directly from CO₂ hydrogenation remains a significant challenge due to its highly exothermic nature which causes the catalyst sintering and deactivation. Herein, we reported a controllable strategy regulating the electronic properties of metallic nanoparticles encapsulated in cages to obtain a highly efficient and stable CO₂-to-CH₄ conversion. The Mn-doped Ni nanoparticles encapsulated in SSZ-13 pores exhibited a CO₂ conversion of 84.62 % and CH₄ selectivity of 98.02 %, approaching the thermodynamic limit of CO₂ methanation and surpassing the previously reported state-of-the-art catalysts. In situ characterizations and theoretical calculations indicated that CO₂ is mainly hydrogenated to produce CH₄ via the key intermediate formate. The electrons are transferred from Mn to Ni atoms and injected into the σ* orbital of CO₂ molecule, promoting the CO₂ activation and conversion into CH₄. This work provides a new avenue for the design of heterogeneous catalysts to achieve the thermodynamic-limit catalytic performance.