Selective CO2 methanation over Ni catalysts on Nb-doped SrTiO3via interfacial electronic engineering

Abstract

The metal–support interface and metal electronic properties critically govern CO₂ adsorption configurations, hydrogen activation efficiency, and subsequent hydrogenation pathways, which significantly affect CO₂ activation efficiency and product distribution. We engineered a Ni/SrTiNbO₃ catalyst through Nb substitution at the B-site of SrTiO₃, which induced electron transfer from Nb to Ni, thereby optimizing the Ni electronic structure and enhancing H₂ activation with efficient hydrogen spillover. This specific Nb–Ni interface facilitated exclusive CO₂ activation via the formate pathway, achieving highly selective CH₄ production. DFT calculations revealed a significantly reduced energy barrier for hydrogen-assisted CO₂ dissociation and a lower rate-determining step barrier compared to Ni/SrTiO₃. The optimized catalyst demonstrated exceptional performance with a CH₄ selectivity of 94.7% and CO₂ conversion of 75.6%, maintaining stability over 200 hours. This work establishes a rational design strategy for selective CO₂ hydrogenation catalysts through precise modulation of interfacial electronic structures and adsorption configurations.