Catalytic center with electrons and molecules enrichment based on quantum tunneling for CO ₂ photoreduction

The design of the catalytic center that facilitates electron accumulation and CO 2 activation is central to enhancing the efficiency and selectivity of photocatalytic CO 2 reduction reactions. Here, a novel quantum tunneling‐assisted catalytic center is constructed based on an architecture comprising an ultrathin MgO film coated on Pt nanoparticles supported on a TiO 2 substrate. This design not only increases electron concentration at the surface active sites but also optimizes surface properties to promote CO 2 activation. As a result, the catalyst achieves a CH 4 selectivity of up to 93.6%, representing a significant advancement in CO 2 ‐to‐fuel conversion. Mechanistic investigations from in situ Fourier‐transform infrared spectroscopy and density functional theory calculations reveal that the MgO surface, which effectively adsorbs CO 2 molecules, exhibits tunable selectivity toward *CHO formation and CO desorption under varying electron concentrations. This work provides new insight for the development of advanced catalytic centers for CO 2 conversion.