Enabling Low-Temperature Methanol Activation via Lattice Oxygen Induced Cu–O–Cr Catalysis

Steam reforming of methanol is a promising approach to achieving hydrogen storage, transportation, and in situ supply. However, this technology is restricted by its high CO selectivity and catalyst deactivation. In this study, CuCr2O4-based catalytic oxygen carriers are tailored for lattice oxygen participating in low-temperature methanol reforming. We found that the low-temperature activation of methanol originated from Cu–O–Cr structure intensification and highly activated lattice oxygen induction. Specifically, methanol can be activated at temperatures as low as 160 °C, on the one hand, attributed to the reinforcement of the Cu–O–Cr structure and, on the other hand, owing to the highly reactive lattice oxygen from the CuO4 tetrahedron in the CuCr2O4 spinel. Combined with XAS and Raman results, the formation of the Cu–O–Cr structure is demonstrated. The hydrogen production rate with an applied CuCr2O4-based catalytic oxygen carrier is 53.2% higher than the control group without Cu–O–Cr formulation. Satisfactory cyclic stability is retained after the 50th lattice oxygen induction and supplement cycle, ascribing to the Cu–O–Cr structure that strongly intensifies Cu–Cr2O3 interactions. DFT results reveal that the process of CH3OH → CH3O* is the rate-determining step. Compared to Cu(111) and Cr2O3(110), the tailored Cu(111)/Cr2O3(110) surface with a Cu–O–Cr structure exhibits the lowest potential barrier during this process, promoting low-temperature methanol reforming.