Ruijuan Zhao, Zhenhua Zhang, Xiaodong Wen
Catalytic hydrogenation of CO2 to formate/formic acid (FA) is a pivotal reaction for realizing a carbon-neutral energy economy, yet its progress is severely hindered by low conversion efficiency. In this review, we focus on oxide-supported Pd catalysts, bridging mechanistic understanding with the development of efficient catalytic systems. Through comprehensive experimental investigations, we systematically elucidate the critical influence of various structural factors on formate/FA production, including the type, crystal phase, and morphology/crystal plane of the oxide support, as well as the particle size and bimetallic alloying degree of the supported Pd species. The catalytic reaction mechanism is also discussed in depth. Our findings reveal that surface basic sites and the electronic properties of supported Pd species (i.e., metallicity) are two crucial factors governing the reaction. This work establishes a systematic structure-activity relationship and a precise structural regulation paradigm, providing theoretical and technical guidance for the development of efficient catalysts and their industrial applications.