Catalytic Co-Oxidation of Acetone and Ammonia over Metal–Organic Framework-Derived Ce–Cu Oxides: Structure–Activity Relationship and Pollutant Interaction Mechanism

Abstract

The simultaneous removal of VOCs and NH3 from industrial exhaust gases poses a formidable challenge owing to the complex interactions between coexisting pollutants. Herein, a series of MOF-derived CeaCubOx catalysts with tunable Ce/Cu ratios were prepared and evaluated for the catalytic co-oxidation of acetone and NH3. Ce2Cu1Ox exhibited the highest catalytic activity, achieving complete conversion of acetone and NH3 at 200 and 250 °C, respectively, while Ce1Cu2Ox showed the highest N2 selectivity (72%). The improved catalytic performance was closely related to the cooperative interaction between Ce and Cu species, which promoted redox capability, oxygen mobility, active oxygen species, and oxygen vacancy formation. In addition, abundant weak acid sites and exposed Cu2+ and Ce3+ species contributed to improved NH3 activation and N2 selectivity. DFT calculations revealed competitive adsorption between acetone and NH3, indicating mutual inhibitory effects during the oxidation process. On the basis of in situ DRIFTS analysis, key surface intermediates and reaction pathways were identified, providing mechanistic insights into pollutant interactions. This work establishes a clear structure–activity relationship for MOF-derived Ce–Cu catalysts and provides guidelines for rationally constructing efficient catalysts toward complex industrial waste gas purification.