Controlled Synthesis Of Copper-based Nanostructured Materials And Properties Study For CO Oxidation

Copper-based nanostructured materials as a kind of catalyst which has abundant source and cheap price, because of its unique physical and chemical properties, its has wide application in catalysis, electronic, antimicrobial, lubricant, photocatalytic and electrochemical aspects. Around these applications, one of the key factors of influence the performance is the shape or surface structure of this kind of materials. In this paper, we tried to prepared a series of different shape of nano Cu and nano Cu₂ O materials by chemical reduction method, Ensured the controllable preparation systems and conditions which can realize batch repeat synthesis and suitable for study catalytic application materials; On this basis, we choose CO oxidation as a pointer reaction to investigate the catalytic performance of different morphology nano Cu₂ O, Found the effect rule of these materials morphology or surface structure for the proper properties of catalytic reaction, which provided a new reference or a new gist for creating more efficient copper-based nanostructured materials and understanding the structure-activity relationship of this kind of materials. The main results are as follows:1. Adopt chemical reduction method, organic solvent diethylene glycol as solvent, copper acetate as copper source, using ascorbic acid as reducing agent, by modulation system consist, we ensured the controlled synthesis conditions which can prepared good dispersancy, strong oxidation resistance, uniform size and the main morphology of copper nanoparticles is hexagonal,and particle size is about 50 nm; Copper sulfate or copper acetate as copper source, glucose as the reducing agent, distilled water or diethylene glycol as solvent, using sodium hydroxide modulation solution p H, we synthesized cube, octahedron, 18-facet polyhedral and porous spherical cuprous oxide nanoparticles, samples were characterized by XRD and SEM, particle size and morphology of polyhedral are uniform, neat,?spherical cuprous oxide particle size is about 200 nm; cube, octahedron, 18-facet polyhedral size are about 1²?m?, In the same or similar system, realizing the controllable synthesis of different morphology Cu₂ O nanoparticles.2. We have a CO oxidation reaction test on the synthetic different morphology Cu₂ O nanomaterials. Primarily, we found that the CO completely conversion temperature is reduce 60? compared after a reaction test samples to fresh samples on porous spherical cuprous oxide nanoparticles, that is, the noteworthy phenomenon of the catalytic performance significantly increased after one reaction test has rarely been reported in literature, In view of this phenomenon, we have done compared characterizations on fresh sample, after one reaction test sample and after repeatedly reaction test sample, by XRD?H2-TPR?XPS?CO-TPD?O2-TPD tests, We found that nano porous Cu₂ O surface will be convert to stable Cu O and Cu₂ O composite interface in in situ reaction process, this kind of composite interface have better activation performance compared to pure Cu₂ O or Cu O surface, thus can showed better catalytic properties. On cube, octahedron, 18-facet polyhedral Cu₂ O nanoparticles, we also found that reused samples showed better property than fresh samples. These results suggest that the surface of Cu₂ O catalysts would in-situ spontaneously convert to a multivalent and stable composite surface in redox reaction atmosphere, Thus can showed better physical and chemical properties. On the one hand, thoes findings and results reveals the real catalytic interface catalysis in Redox reaction of Cu₂ O nanomaterials, offering new gist for understanding the catalytic properties of Cu₂ O nanomaterials; On the other hand, showing a new method to modulation Cu₂ O surface structure, thus provide a new reference to create a better physical and chemical properties of Cu₂ O based materials.