Hierarchical sheet-like Cu/Zn/Al nanocatalysts derived from LDH/MOF composites for CO2 hydrogenation to methanol

Abstract The CO 2 hydrogenation to generate methanol is one of the most promising techniques to turn waste CO 2 into useful fuel and chemicals in a sustainable manner. Herein, we have designed several hierarchical sheet-like Cu/Zn/Al nanocatalysts to efficiently produce methanol from CO 2 hydrogenation by a rational integration of layered double hydroxide (LDH) nanosheets and metal-organic frameworks (MOF) nanoparticles as double solid precursors. Specifically, the uniform loading of Zn-BTC nanoparticles on CuAl LDH surface was achieved by an in-situ growth method at mild conditions. It was found that the pretreatment of the LDH with acetone could effectively exfoliate the sheet-like structure, increase the specific surface area, and facilitate the immobilization of Zn-BTC nanoparticles, which remarkably improved CO 2 hydrogenation performance with respect to methanol selectivity (>90% at 200°C). It was found that both the existence of Zn-BTC and the pretreatment of LDH with acetone significantly reduced CO selectivity by increasing the activation energy (Δ(E a ) up to 20 KJ/mol). Moreover, in-situ DRIFTS study indicates that the promoting effect of ZnO (derived from Zn-BTC) on methanol formation is mainly associated with the formation of a higher amount of * CH 3 O intermediate rather than * CO and * HCOO species on the catalyst surface.