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Abstract Precise manipulation of catalyst structure at atomic level holds the key to regulating the catalyst performance. Herein, we show that single Cr atom doping in In2O3 can modulate the In-O bond with significantly improved performance in CO2 hydrogenation to methanol. A “distance effect” concept is proposed to interpret the function of Cr doping, wherein Cr stimulates the directly coordinated oxygen to form Cr and In confined oxygen vacancy (Ov) active sites for the enhancement of CO2 activation and lowering the energy barrier for the HCOO* to H2COO* transformation (the rate-determining step). In addition, Cr assists in maintaining the structure stability and inhibits the over-reduction of In2O3 through the tethering of nearby oxygen atoms. The Cr-In2O3 catalyst exhibits a CO2 conversion of 9.4% and CH3OH selectivity of 92.0% under the reaction conditions of 250°C, 5 MPa, and 3000 mL·gcat−1·h− 1, along with a remarkable stability over 500 h on-stream testing. This study demonstrates a new paradigm for the modulation of In-O bonds in In2O3-based catalysts to break the trade-off between the reactivity and stability of the CO2 hydrogenation reaction.
Huang et al. (Fri,) studied this question.