Activation of Co-O bond in (110) facet exposed CoO by Cu doping for the boost of propane catalytic oxidation.

Defects engineering in metal oxide is an important avenue for the promotion of VOCs catalytic oxidation. Herein, the influence of crystal facet of CoO is first investigated for the propane oxidation. An intelligent Cu doping is subsequently performed in the most active (110) facet exposed CoO catalyst. The optimized Cu-CoO-110-3 catalyst exhibits a prominently enhanced activity with propane conversion rate of 1.9 μmol g s at reaction temperature of 192 °C and the propane mass space velocity of 60,000 mL g h, about 2.4 times that of the pristine CoO. Systematic experimental characterizations (XAS, EPR, Raman, TPR, XPS, etc.) combined with density functional theory calculations point out that the incorporated Cu could increase the electrophilicity of nearby O atom and implant beneficial defect structures (lattice distortion, coordination unsaturation, abundant oxygen vacancies, etc.), which could significantly activate Co-O bond in CoO, leading to the facilitated generation of active oxygen species as well as promoted oxidation ability. This study could set an illuminating paradigm for the boost of the intrinsic oxidation activity by the precise defect construction in CoO catalyst, which will help drive ahead the pursuit of non-precious metal catalyst for VOCs abatement.