Construction of unique oxygen vacancy defect through various metal-doping (Cu, Mn, Zr) of Ce2Co1Ox nanoparticles towards boosting the catalytic oxidation toluene performance

Abstract

Achievement of catalytic oxidation of volatile organic compounds (VOCs) at low temperature is still a challenge to be addressed. Promoting catalytic activity via constructing oxygen vacancy defect is an attractive strategy in heterogeneous catalysis. Herein, a series of Ce2Co1M1 (M = Cu, Mn, Zr) catalysts were prepared by modified co-precipitation method and their catalytic oxidation performance of toluene was measured. Activity results suggested that the introduction of doping-metals significantly enhanced the catalytic performance of Ce2Co1Ox, with Ce2Co1Cu1 possessed the optimal catalytic activity (T90 = 210 ℃), robust stability, water resistance, GHSV tolerance and anti-aging ability. It has been demonstrated that Cu-doping resulted in the formation of Cu-Ce solid solution and constructed a Cu2+-O-Ce4+ complex active site. Benefiting from this, the redox and gaseous oxygen molecule capture & activation capabilities of the catalyst are tremendously improved via constructing abundant oxygen vacancies. The in-situ DRIFTS results revealed that Ce2Co1Cu1 exhibited a better C=C breaking of aromatic rings ability, a faster consumption rate of benzoate and maleic anhydride, and is less prone to accumulation of by-products, the above account for its enhanced low-temperature catalytic performance for toluene. This work may provide a new strategy to design the high-efficiency toluene oxidation catalysts.