Abstract:
CO
2 catalytic conversion with green hydrogen into high value-added chemicals is an important approach to achieve large-scale CO
2 emission reduction, green hydrogen storage and transportation, which is great significance for advancing the “Dual Carbon” goals and facilitating the transition to green energy. However, traditional thermal catalytic CO
2 hydrogenation technologies usually rely on high-temperature conditions, which have problems such as harsh reaction conditions, high energy consumption, easy deactivation of catalysts, and difficulty in regulating product selectivity. In recent years, photothermal catalysis for CO
2 hydrogenation has developed rapidly. Compared with thermal catalysis technology, photothermal catalysis can couple renewable solar energy resources, reduce the use of fossil energy, and at the same time achieve CO
2 hydrogenation reactions under mild conditions, improving the operational stability of the catalyst to a certain extent, which has attracted extensive attention from both the academic and industrial communities. However, due to the chemical inertness of CO
2 molecules and the complexity of reaction pathways, the generation of different products involves competing reaction pathways, making it extremely challenging to achieve efficient and targeted photothermal catalytic conversion of CO
2. In recent years, researchers have made significant progress in improving the CO
2 conversion rate and optimizing the selectivity of target products through strategies such as designing efficient photothermal catalysts, optimizing reaction systems, and exploring the photothermal synergy mechanism. Based on this, this paper systematically summarizes the research progress of photothermal catalytic CO
2 hydrogenation. Firstly, the photothermal catalytic CO
2 hydrogenation reaction and catalyst systems are introduced. The new catalyst system for preparing CO, CH
4, methanol and C
2+ products by photothermal catalytic CO
2 hydrogenation was summarized. The photoelectronic effect or photothermal conversion effect produced by photothermal materials (such as metal nanoparticles, semiconductors, MOF materials, etc.) under light conditions was studied. The photogenerated carriers are excited and the rapid temperature rise of the reaction system is promoted to participate in the catalytic process, and the structure-activity relationship between the composition, structure (such as particle size, defects, interfaces) of the catalyst and the reaction performance is explored. Secondly, the mechanism of photothermal catalytic CO
2 hydrogenation reaction was summarized, and the regulation mechanism of photothermal catalysis on product selectivity and reaction performance was introduced. On the one hand, by lowering the energy barrier of the key reaction path, the reaction is more inclined to generate specific products, significantly enhancing the selectivity of the target products. On the other hand, electron transfer can optimize the adsorption and conversion kinetics of reactants such as CO
2, *CO, and *HCOO, as well as key intermediate species, thereby accelerating the reaction process. Finally, the development prospects of photothermal catalytic CO
2 hydrogenation are prospected. At present, the development of photothermal catalysis technology still faces challenges such as unclear reaction mechanisms, low utilization rate of catalyst light energy, and poor long-term stability. In the future, it is necessary to develop full-spectrum response materials, regulate and achieve the selectivity of specific products (such as C
2+), improve the stability of the catalyst, develop highly stable catalysts, and conduct in-depth research on the photothermal synergy mechanism to achieve industrial application.