Low-temperature efficient catalytic oxidation of acetonitrile over Cu and Ce co-doped perovskite-type LaMnO3 catalyst

This work develops Cu and Ce co-doped LaMnO3 perovskite catalysts via sol-gel synthesis for low-temperature catalytic oxidation of toxic acetonitrile. Optimized La0.9Ce0.1Mn0.9Cu0.1O3 achieved 90 % acetonitrile conversion at 215 degrees C with N-2 selectivity > 98 %, surpassing monometallic counterparts. Structural analysis revealed that Cu/Ce co-doping induced lattice distortion and oxygen vacancy formation, enhancing O-2 activation and Mn3 +/Mn4+ redox cycling. In-situ DRIFT studies unveiled a dual reaction pathway: hydrolysis-dominated conversion to acetamide/NH3 at low temperatures (<200 degrees C) and oxidation-driven -NCO intermediate formation at elevated temperatures. Significantly, NH3 generated from hydrolysis participated in in-situ selective catalytic reduction of NOx to N-2, minimizing secondary pollution. The catalyst maintained robust stability under industrial conditions (GHSV = 300,000 h(-1)) after thermal cycling. This work provides mechanistic insights into perovskite-mediated nitrile degradation and demonstrates a design strategy for energy-efficient emission control systems targeting industrial HCN/acrylonitrile pollutants.