摘要
Cu-based catalysts are promising for CO 2 -to-methanol conversion, but their activity and stability are usually compromised by the accumulation of byproduct water. Although physically mixing hydrophobic additives with Cu-based catalysts can facilitate water removal, how to regulate the water-removal kinetics in this process, as well as its impact on the reaction kinetics of CO 2 hydrogenation to methanol, remains insufficiently understood. Herein, by modifying the polydivinylbenzene (PDVB) with porosity, we regulate the surface hydrophobicity of its mixture with a layered double hydroxide (LDH)-derived CuZnAlMg catalyst, thereby enhancing the water removal kinetics on the mixed catalyst surface. In contrast to nonporous PDVB, porous PDVB, with a substantially higher surface area and abundant mesopores, effectively creates additional H 2 O transfer channels. This facilitates rapid water removal, which in turn inhibits the oxidation of Cu nanoparticles and ensures the re-exposure of oxygen-vacancy active sites for sustained catalysis. Furthermore, water removal also accelerates the formation and subsequent hydrogenation of intermediates for higher activity. Consequently, a high space-time yield of methanol of 519.89 g MeOH kg cat –1 h –1 and a CO 2 conversion rate of 26.35% are achieved at 5 MPa and 260 ° C. The mixed catalyst exhibits excellent stability over 200 h of continuous operation. This work offers a simple yet robust strategy for regulating catalyst hydrophobicity toward efficient CO 2 hydrogenation to methanol.
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