Preparation Of Copper-catbon Foam And Its Electrocatatic Performance Of CO₂ Reduction

With the rapid development of industry and the increasing demand for fossil fuels,the rapid increase in the concentration of CO2 in the atmosphere has induced a series of environmental problems such as rising global temperatures and rising sea levels.CO2 electrocatalytic reduction is an effective way to realize the utilization of CO2 resources.Therefore,the development of high-efficiency catalytic systems has important theoretical and practical significance for the effective utilization of CO2.In this paper,the metal copper(Cu)catalyst,which can reduce CO2 to hydrocarbons,is supported on porous carbon foam with high conductivity,high specific surface area,good chemical stability to prepare a CO2 electro-reduction catalyst with good comprehensive application performance.And the effect of microstructure changes on its CO2 electro-catalytic reduction performance were studied.The research work carried out in this paper mainly includes the following contents:(1)The preparation of phenolic-based porous carbon foam(CF).The macroporous phenolic foam was prepared by the emulsion template method and then carbonized in a nitrogen atmosphere to prepare the carbon foam.Its structure was characterized by SEM,BET,Raman spectroscopy,XRD,etc.The results show that by changing the volume fraction of the dispersed phase in the emulsion system,the carbonization temperature,adding the co-emulsifier F127 and carboxyl carbon nanotubes,the cell structure of the carbon foam can be adjusted.When the addition amount of carboxyl carbon nanotubes is 5%,the volume fraction of the dispersed phase is 70%and the carbonization temperature is 800℃,a carbon foam with interconnected pores and larger specific surface area is prepared.(2)Study on the preparation and performance of copper surface modified carbon foam(Cu/CF).Using self-made carbon foam as a carrier,a carbon foam with metallic copper on the surface was obtained by solvothermal reduction method and its microstructure and electrocatalytic properties were studied.By controlling the concentration of Cu2+,the Cu loading on the carbon foam was adjusted and the electrocatalytic performance was studied.The results show that:when Cu2+is 0.1M,the current density of Cu/CF prepared can reach 0.084A/cm2 and the Faraday efficiency of the total liquid phase product is about 18.75%at-1V(vs.RHE).(3)Study on preparation and performance of copper-loaded carbon nanotube doped carbon foam(Cu@CNTs/CF).First,Carbon nanotubes loaded with copper nanoparticles(Cu@CNTs)were prepared by the high-temperature liquid-phase reduction method.By controlling the ratio of Cu2+,PVP and carboxyl carbon nanotubes,carbon nanotubes uniformly wrapped by copper nanoparticles were prepared.Then it was added to the emulsion template system and the Cu@CNTs doped carbon foam(Cu@CNTs/CF)was obtained by one-step method.The microstructure and electrocatalytic performance of the carbon foam with different copper loadings were studied.The results show that:when the Cu@CNTs addition amount is 5%,the current density of the prepared carbon foam can reach 0.03A/cm2 and the Faraday efficiency of the total liquid phase product is about 17.8%at-1V(vs.RHE).