Preparation Of Dual-mode Nanoporous Copper By Dealloying And Its Catalytic Performance

The preparation of nanoporous?np-?metals by dealloying method is simple and effective for obtaining nanoporous structure with high internal surface area,high porosity and relatively uniform pore size.In addition,nanoporous metals not only retain the high thermal conductivity,high conductivity and other excellent performance of metal materials,but also have a unique nature that the block metals do not have?such as high catalytic capacity?due to their nano-level feature.Therefore,nanoporous metal and dealloying method have aroused more and more attention in recent years.At present,dealloying is used to prepare np-metals?such as np-Au,Pt,Pd,Ag,Cu,etc.?,np-alloys?such as np-AuPt,PtPd,AuAg,etc.?.Although precious metals?alloys?have excellent performance,the study of nature lively copper not only has the value of scientific research,but also provides guidance for the rational use of copper resources.In this paper,porous alloy precursors were prepared by alloying Al-Cu?Na Cl?alloy by means of ball milling-mechanical alloying and cold pressing-sintering method followed by a water bath to remove the NaCl template.And finally the copper/copper oxide of the double-stage pore structure was obtained.First,Al₆₇Cu₃₃ was selected as the object of study.Al,Cu,and NaCl powders were uniformly mixed by ball milling,and the mixture was sintered at room temperature?hereinafter referred to as cold pressing-sintering?.The effect of sodium chloride,sintering temperature and sintering time on the structure and composition of nano-porous copper/copper oxide were studied.And then its dealloyed products were used in the catalytic degradation for methyl orange?MO?and supercapacitor performance test.The second one is to mix different proportions of Al,Cu,NaCl powders by lower speed grinding instrument.Al-Cu?NaCl?alloy with different NaCl ratio was prepared by cold pressing-sintering,and the double-layer nanoporous copper/copper oxide was obtained by desalting-dealloying.The optimum salt content of Al-Cu alloy was determined by ultrasonic photocatalytic degradation for MO by nano-porous copper/copper oxide.Then,supported gold catalysts were prepared by electroless plating on the surface of the dealloyed products.Finally,the optimum process parameters were determined according to the feasibility of the catalytic activity of CO.The theory of catalytic CO oxidation by supported gold catalysts.The Al-Cu alloy was prepared by cold pressing-sintering.The optimum salt content of Al-Cu alloy was 5 wt.%.The reason is that two different sizes of pores are formed in the dealloyed products,and the funtions of two channels are different: the larger pore? 1000 nm?accelerates the diffusion.The smaller pore? 40 nm?is beneficial to increase the specific surface area and thus provide more chemical reactivity sites.This nanoporous material with a double-layer structure has a better catalytic efficiency than nanoporous materials with only single-scale ranges of pores.The dealloyed products are usually Cu/Cu2 O.When the products are Cu/CuO/Cu2 O,the catalytic efficiency is the highest.The noble metal Au particles were redeposited on the surface of nanoporous copper/copper oxide by replacement.The effects of supported Au catalyst on the catalytic oxidation of CO in the whole catalyst,including temperatures that the percent conversion of CO was 100%,the conversion of CO at the temperature,and the principle of catalyzing CO oxidation catalyzed by supported catalysts,were studied.It was found that the catalytic efficiency of nanoporous copper/copper oxide supported on Au nanoparticles was higher than that of unsupported significant increase?up to 27%?due to the synergistic effect between the Au and the carrier on the surface of the dealloyed product substrate.