Research On Preparation Of Copper-based Nanomaterials And Their Catalytic Performance

Currently, the issue of resource shortage has been increasingly prominent and the resource consumption has been approximating the limit of environmental carrying capacity. How to reduce the waste of the limited resources and elevate their utilization rate has been a focus of people’s attention. The catalysts widely used currently are dominated by such precious metals with excellent properties as gold, platinum, palladium, silver etc. but they have limited reserves and high prices. In addition, most of the precious metals in the nucleus will be wasted due to the fact that their catalytic activity components are on the surface of the nanoparticles. Introduction of such cheap metals as Fe, Ni, Cu etc. is an effective method to save the production cost of precious metal catalysts. The resource utilization rate can be elevated and the consumption of precious metals can be reduced by using the nano preparation technique and substituting the copper for precious metals. Thus, preparation of composite materials with a novel structure and excellent properties is significant theoretically and practically. Much progress has been made in the controlled synthesis of copper nanomaterials but it is still significant to explore the influencing factors during generation of cooper nanomaterials, design a simple and feasible synthetic route, prepare nanomaterials with a novel morphology, and expand their applications.The paper aims to synthesize copper crystals and copper-based composite nanomaterials with a novel morphological structure by appropriate means and study their properties in catalysis. A study was conducted for the structure, morphology, photoelectric properties, and catalytic properties of the synthesized catalyst tested by such test methods as XRD, SEM-EDS, TEM, DRS, UV-vis, ICP, EA. The results are as follows:1. A micro-nano copper crystals with a novel morphological structure was prepared by using Cul and VCNa under controlled reaction conditions with the solvothermal method. There has been no relevant report on shuttle-shaped, pompons-shaped, and flower-shaped products. Research was conducted for the growth process of the micro-nano copper and simple discussion was made for the growth mechanism of the micro-nano copper. An appropriate study was conducted for the catalysis during the ligation reaction between phenylacetylene and azidomethyl using the copper micro-nano material prepared above. Comparisons of catalytic activity were made among various micro-nano copper and the copper micron flower had the best catalytic performance.2. Nano-copper particles with a controllable size were prepared by the method of reversed microemulsion. An investigation was made to examine the effect of the dosage of the reductant of the sodium borohydride on preparation of the copper nano particles. Research on preparation of nano-copper was made with various copper salts as the precursors and the results showed that pure nano-copper could be prepared by using copper chloride and copper acetate while pure ano-copper could not be prepared with copper nitrate. Copper nano particles with a uniform morphology and controllable size were successfully prepared by controlling the proportion of the water phase and emulgator in the reverse microemulsion systems.3. Nano-composite materials of Cu@Ag and Cu@Ag/RGO core-shell structure were prepared with the method of reversed microemulsion. Appropriate characterization was performed for the microstructure and composition of the nanomaterial prepared by such testing methods as XRD, TEM, EDS, UV-vis, ICP, EA etc. Based on a comprehensive analysis of the results from various characterizations, the Cu@Ag nano particles were really ones of core-shell structure (copper core and silver shell). The analysis showed that Cu@Ag core-shell nano particles were able to densely distribute on the surface layer of RGO. And, their structure was the same as that of the unloaded core-shell nano particles. A hydrogenation catalysis study was conducted for the nanomaterials obtained. The result indicated that catalytic performance of the Cu@Ag and Cu@Ag/RGO nano core-shell materials prepared was very excellent. And the catalytic performance of Cu@Ag/RGO was better than that of Cu@Ag.4. Nanomaterial with a novel structure was prepared by use of reversed microemulsion. It is core-shell structure with copper as the core and noble metals such as gold, platinum, palladium as the shell. Appropriate characterization was performed by XRD, TEM, EDS, UV-vis, ICP for the for the microstructure and composition of the nanomaterials prepared. Based on a comprehensive analysis of the results from characterization of the various nano particles, it could be concluded that the nanomaterials prepared were really nano particles of core-shell structure with copper as the core and gold, platinum, and palladium as the shell. In addition, core-shell materials with controllable components were prepared by controlling the amount of precious metal salt added. A hydrogenation catalysis study was conducted for the core-shell material obtained. The results showed that the catalytic performance of all core-shell nanomaterials prepared was far more higher than that of pure copper and precious metal materials.5. Nanomaterial with a novel structure was prepared with the method of reversed-phase microemulsion. It is of core-shell structure with RGO-loading copper as the core and the precious metals of gold, platinum, palladium etc. as the shell. Appropriate characterization was performed for the microstructure and composition of the composite nanomaterial prepared by such testing methods as XRD, TEM, EDS, UV-vis, ICP, EA etc. Based on a comprehensive analysis of the results from characterization of various composite nano particles, it could be concluded that the composite nanomaterial with RGO-loading Cu@(Au, Pt, and Pd) nano particles had been successfully prepared. Various composite nano particles were able to densely distribute on the surface layer of RGO. And, their structure was the same as that of the unloaded core-shell nano particles. A hydrogenation catalysis study was conducted for the nanomaterials obtained. The result showed that the catalytic performance of the RGO-loading Cu@(Au, Pt, and Pd) nanomaterials prepared significantly improved compared with the core-shell nano particles unloaded with RGO. And the catalytic performance was much better than appropriate pure RGO-loading copper, gold, platinum and palladium materials.