N-doped Co3O4 catalyst with a high efficiency for the catalytic decomposition of N2O

Abstract

l N-doped Co 3 O 4 catalysts were synthesized by a facile g-C 3 N 4 -modified sol-gel method. l N-doped Co 3 O 4 catalysts showed superior N 2 O decomposition activity than the pristine Co 3 O 4 . l N-doping facilitated the creation of defective structure, surface Co 2+ , and basis sites on the catalyst. l Introduction of N improved the electron donation ability of Co 2+ and enhanced the redox property of Co 3 O 4 . A series of defective N-doped Co 3 O 4 catalysts, N-Co 3 O 4 - x ( x = 0.002, 0.01, 0.05, 0.15, and 0.25), were prepared by a facile graphitic carbon nitride (g-C 3 N 4 )-modified sol-gel method, and their catalytic behaviors for N 2 O decomposition reaction were evaluated. The activity tests indicated that all the N-Co 3 O 4 - x catalysts showed superior activity than the pristine Co 3 O 4 , and N-Co 3 O 4 –0.05 exhibited the best activity with 100% N 2 O conversion at a reaction temperature of 380 °C, ca. 160 °C lower than that of Co 3 O 4 . N-Co 3 O 4 –0.05 also showed high catalytic activity and stability in the presence of impurity gasses (O 2 , NO, and/or H 2 O) at varying reaction conditions. Based on the employed systematic characterization techniques, the successful doping of N atoms into Co 3 O 4 was confirmed. The N-doping facilitated more defective structures (namely oxygen vacancies), surface Co 2+ , and basic sites on Co 3 O 4 . In addition, N-doping contributed to enlarging the surface area, improving the electron donation ability of Co 2+ , enhancing the redox property of Co 3 O 4 , and weakening the Co-O bond. All these factors promoted the performance of N-Co 3 O 4 –0.05 for N 2 O decomposition. This work provides a simple strategy to construct advanced N-doped Co 3 O 4 material for N 2 O decomposition applications and other catalytic reactions.