Defect-engineered CuxO/CeO2 catalysts: Enhanced low-temperature CO preferential oxidation through dual-promotion of CO adsorption and O2 activation

Abstract

The preferential oxidation of CO (CO-PROX) represents a critical strategy for trace CO elimination in hydrogen purification, where CO adsorption and O₂ activation are crucial for enhancing catalytic performance. Herein, we report a defect-engineered strategy mediated by MOF to promote CO adsorption and O₂ activation. By pyrolyzing Ce-BDC MOF, we synthesized CeO₂–O support with a high–density mesoporous structure and high surface area, facilitating the well-dispersion of CuₓO species and forming abundant interfacial Cu⁺ active sites. The well-dispersed Cu_xO species enhance their interaction with CeO₂–O, resulting in weakened Ce–O bonds and promoting both lattice oxygen activation and oxygen vacancy (Vo) formation for enhanced O₂ activation. The optimized 15Cu_xO/CeO₂–O catalyst demonstrates exceptional catalytic efficiency, achieving complete CO conversion at a comparatively low temperature (T_{100 %} = 115 °C), coupled with broad temperature window applicability and outstanding stability over multiple cycles. This work establishes a MOF-guided paradigm for engineering multifunctional catalytic sites, offering a generalizable approach to design high-performance oxide catalysts for hydrogen purification and beyond.