Insight into the Synergistic Effect of Binary Nonmetallic Codoped Co3O4 Catalysts for Efficient Ethyl Acetate Degradation under Humid Conditions

The synthesis of high-performance catalysts for volatile organic compounds (VOCs) degradation under humid conditions is essential for their practical industrial application. Herein, a codoping strategy was adopted to synthesize the N–Co3O4–C catalyst with N, C codoping for low-temperature ethyl acetate (EA) degradation under humid conditions. Results showed that N–Co3O4–C exhibited great catalytic activity (T90 = 177 °C) and water resistance (5.0 vol% H2O, T90 = 178 °C) for EA degradation. Characterization results suggested that the C, N codoping weakened the Co–O bond strength, increased surface Co3+ and Oads species, and improved the low-temperature redox ability and the mobility of lattice oxygen species, which boosted the catalytic performance of N–Co3O4–C for EA degradation. Meanwhile, the N-doping-induced oxygen vacancies could interact with water vapor to generate extra active oxygen species, which enhanced the water resistance. Importantly, based on a series of characterization technologies, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and theoretical calculations, the synergistic effect of C, N codoping was systematically investigated and elucidated. The C doping induced the increase of surface area and the weakening of Co–O bond strength, which improved EA adsorption and lattice oxygen species activation to dissociate and oxidize EA, forming the key intermediate, acetate acid. N doping enhanced the adsorption and activation of gaseous oxygen species to form active oxygen species, attacking and breaking the C–C bond in acetate acid to accelerate EA deep oxidation, which synergistically facilitated EA degradation.