Effect of the precipitation pH on the characteristics and performance of Co3O4 catalysts in the total oxidation of toluene and propane

Co3O4 catalysts were prepared via carbonate precipitation at different pH, characterized using TG/DTA, FTIR, XRD, Raman, N2 adsorption and TPR techniques, tested in the total oxidation of toluene or propane. The pH may affect composition cobalt oxide precursors as well physicochemical properties performance catalysts. By controlling 9.5, a catalyst with smallest crystalline size, largest surface area, most defective structure, best reducibility was obtained. activity as-prepared linearly dependent on low temperature oxide. Among all catalysts, Co-9.5 exhibited highest catalytic (T10 = 197 °C T90 244 °C), excellent cycling-stability good durability upon long-term test. In propane oxidation, residual sodium had marked poisoning effect performance, evidencing importance washing procedure preparation.