Synthesis of Co3O4 catalysts with different morphologies and their excellent catalytic performance for soot combustion

Soot particles released from diesel engines have resulted in significant environmental pollution and have been widely recognized as an important factor for haze weather conditions. Soot emissions can be effectively mitigated using catalytic purification technologies, which necessitate the development of high-efficiency catalysts. Co3O4 catalysts with flower-, rod-, urchin-, sheet-, and cube-like morphologies were prepared via a hydrothermal method and were analyzed using characterization methods including XRD, SEM, and H2-TPR. Compared to the other synthesized catalysts, the urchin-like (Co3O4-U) catalyst exhibited better redox ability, stronger oxygen adsorption and activation ability, and the ability to convert NO into NO2. Therefore, the Co3O4-U catalyst displayed the best catalytic activity for soot combustion, with T10, T50, and T90 values of 274 degrees C, 327 degrees C, and 359 degrees C, respectively. Moreover, based on the characterization and catalytic performance results, the reaction mechanisms for the Co3O4-U catalyst were proposed. The Co3O4-U catalyst possesses advantages such as a simple preparation process, economic feasibility, and excellent catalytic performance.