Metallic engineering in metal-porphyrin frameworks for highly efficient CO2 photoreduction.

Specific spin states of metals with 3d5, 3d7, and 3d8 electronic configurations were engineering on metal-porphyrin frameworks SNNU-600-M. SNNU-600-Ni (S = 0) achieved an exceptional CO yield (21697.6 μmol g−1 h−1) and high selectivity. This study highlights the significance of electronic configuration on enhancing reduction ability and regulating kinetics for efficient CO 2 photoreduction, offering new insights into photocatalysis. [Display omitted] • Efficient metallic engineering on single-crystal MOFs was reported. • SNNU-600-Ni exhibits ultrahigh CO yield (21697.6 μmol g−1 h−1) and selectivity (90 %). • Electronic configuration engineering plays one-stone-two-birds effect on activity. • Ni(II) enables the proton adsorption on neighbor N site and regulates kinetics. CO 2 photoreduction is an environmentally friendly technique to reduce carbon emissions and produce value-added products, but the poor efficiency and low selectivity restricted its applications. Here we proposed a one-stone-two-birds strategy, metallic engineering, to boost CO 2 photoreduction performance, in which the improved reduction ability and the regulated CO 2 reduction kinetics can be simultaneously achieved. The electronic configurations of 3d5, 3d7, and 3d8 with S = 1/2, 1/2, and 0 spin ground states were successfully constructed via metal engineering on metal-porphyrin frameworks (SNNU-600-M). Among SNNU-600-M catalysts, SNNU-600-Ni (S = 0) exhibites ultrahigh CO yield (21697.6 μmol g−1 h−1) with high selectivity. The 3d8 electronic configuration of Ni(II) on the one hand signficantly improve the reduction ability. On the other hand, due to the instinctive unstable feature of 3d9 for Ni(I) after photoexcitation, the photoinduced electron enables the proton adsorption on the neighbor N site, regulates the kinetics and facilitates the generation of key intermediate *COOH, leading to efficient CO production. This work provides a new insight into the electronic configuration regulation for efficient photocatalysis. [ABSTRACT FROM AUTHOR]