Dual active sites constructed in MIL-125(Ti)-derived high stability CuNi/TiO2 catalyst for enhanced RWGS reaction

Successfully tailored a dual-site architecture comprising Cu + /Ni δ+ -O V -Ti and CuNi NPs on the ultra-small TiO 2 support-derived from MIL-125(Ti). • Deeply revealed the defect rich Cu + /Ni δ+ -O V -Ti site promotes CO 2 adsorption, while the CuNi NPs with electron redistribution facilitates H 2 adsorption and desorption of the product CO. • Significantly enhanced the RWGS reaction activity and sintering-resistance. Copper (Cu)-based catalysts hold promise for the reverse water-gas shift (RWGS) reaction because of their 100% selectivity toward CO. However, their low intrinsic activity, and deactivation caused by irreversible sintering during RWGS reaction remain persistent challenges. Herein, we report a pore adsorption strategy to simultaneously achieve electronic structure modulation and preserve microstructure stability during the RWGS reaction. Specifically, a MOF-derived TiO 2 -supported CuNi catalyst is constructed with dual active sites consisting of Cu + /Ni δ+ -O V -Ti sites and CuNi nanoparticles (NPs). The optimized catalytic performance achieves CO 2 conversion of 37.1% with CO selectivity of 99.9% and operates stably for 200 h at 450 ℃, placing its performance among the advanced Cu-based catalysts reported to date. Atomic/electronic structure characterization and density functional theory calculations demonstrate that Cu + /Ni δ+ -O V -Ti sites with enhanced charge redistribution capability promote CO 2 adsorption. The CuNi NP sites with electronic interaction enhance H 2 adsorption and moderate CO adsorption. This work provides a rational design strategy for highly active, selective and stable Cu-based RWGS catalysts. Download: Download high-res image (286KB) Download: Download full-size image Dual active sites consisting of Cu + /Ni δ+ -O V -Ti sites and CuNi NPs are constructed in the MOF-derived CuNi/TiO 2 catalyst, enabling electronic modulation and structural stabilization for enhanced RWGS reaction.