Preparation Of Cu₂O Based Nanocatalyst And Its Catalytic Performance In Rochow Reaction

In heterogeneous catalysis,the design and construction of the desired semiconductor and metal interface are critical to catalytic function due to the significant interfacial effects However,there are still challenges and obscurities in understanding and constructing interfacial sites and semiconductor and metal interaction mechanisms.Rochow reaction is important industrial process for synthesizing organosilicon polymers,construction of different Cu₂O based catalysts in the rocow reaction is an effective way to improve the M2 selectivity and Si conversion,and is also one of the research hotspots in recent years.In this paper,a series of Cu/Cu₂O(metal-semiconductor),Cu/Cu₂O/ZnO(metal-semiconductor-semiconductor)materials,heterostructure materials,were constructed based on Cu₂O nanomaterials with specific morphology.The structure-activity relationship between catalyst and catalytic performance was established by characterization and performance tests.Based on this,the following research work is carried out in this paper:(1)A series of cubic Cu/Cu₂O hetero-nanoparticles were synthesized by in-situ surface restructuring cubic Cu₂O nanoparticles via a simple reduction treatment.It is found that cubic Cu/Cu₂O with appropriate heterointerfaces exhibited the improved dimethyldichlorosilane(M2)selectivity,Si conversion,and stability.This is because of the presence of a strong interaction between the Cu/Cu₂O interface,which is attributed to the formation of Schottky junctions that enhance the charge transfer efficiency,and the subsequent reduction of Cu⁺into Cu*(the active Cu atoms).(2)Moreover,the easier cleavage of Si-Si bond along{110}crystal plane effectively generates Si*(the free Si atoms),which leads to inclined grooves on the surface of Si particles.The established transport and diffusion channel of Cu*and Si*greatly promoted the formation of Cu₃Si active phase and the subsequent methyl chlorosilane.(3)ZnO nanoparticles loaded on Cu/Cu₂O nanoparticles,and the Cu/Cu₂O/ZnO nanocatalyst showed better catalytic performance.On the one hand,the establishment of PN heterostructure can promote the rochew reaction;on the other hand,the calculation of core energy level shows that the addition of metal will increase the energy band offset and enhance the adsorption of Me Cl,which is beneficial to the catalytic reaction.