Catalytic Combustion of Toluene over Cobalt Oxides Supported on Graphitic Carbon Nitride (CoOx/g-C3N4) Catalyst

Graphitic carbon nitride (g-C3N4) supported CoOx catalysts were prepared by the impregnation method and comprehensively characterized by XRD, N2 physisorption, TEM, H2-TPR, and XPS. The catalytic performance tested by catalytic combustion of toluene indicates that 10% CoOx/g-C3N4 catalyst exhibits the highest activity, achieving a toluene conversion of 90% at a temperature of approximately 279 °C, compared with other CoOx catalysts supported on SBA-15, γ-Al2O3 and activated carbon (AC). The specific structure of g-C3N4 made it a N and electron-rich material, which might be the reason for the existence of Co3O4 active phase, high surface Co3+ content and high density of surface oxygen adsorption species, and facile reducibility of Co3+. Moreover, no significant decrease in catalytic efficiency is observed over different temperature stages on the 10% CoOx/g-C3N4 sample, which indicates that the catalyst’s stability is excellent under the conditions required for toluene combustion.