A Review of the Application of Soot Catalysts: Focus on the Soot Oxidation-Induced Fragmentation Process

Diesel soot is well-known for its adverse effects on both the environment and public health, sparking significant academic interest. The use of diesel particulate filters (DPFs) represents an effective strategy for capturing and subsequently removing soot particles. However, the captured soot cannot be oxidized under exhaust conditions, and the additional fuel consumption is required to increase the oxidation temperature. The addition of catalysts can effectively reduce the oxidation temperature of soot, improve the oxidation efficiency, and save energy consumption. The widespread adoption of catalyst-coated DPF systems is largely dependent on the development of effective catalysts. This review compiles the application of catalysts in the field of diesel engine soot removal, with a focus on the influence of catalyst on soot physicochemical properties in the oxidation-induced fragmentation process. It begins with an in-depth discussion of the various catalytic mechanisms of different soot catalysts, and the factors that affect the catalytic activity are further explored. Then, this review focuses on the effects of catalysts on soot physicochemical properties in the oxidation-induced fragmentation process, and the potential synergistic effects generated by the interaction between catalysts and environmental components in the exhaust gas are further analyzed. Finally, the applications of catalysts in soot removal engineering are concluded. The review provides key insights for future research efforts aimed at enhancing catalyst efficiency.