Preparation Of Cu-based Catalysts And Their Electroreduction Of CO₂ To Alcohols

In an ideal situation,the CO₂ produced on earth should be balanced with what is consumed,so that the level of CO₂ remains constant to maintain environmental stability.Unfortunately,with the intensification of industrial activities,this balance has gradually been disrupted,leading to more CO₂ production and making global warming a pressing issue.Therefore,reducing CO₂ production and converting CO₂into useful chemical products seems to be necessary.Carbon dioxide can be reduced to multiple hydrocarbons.Ethanol has a wide range of uses in defense and chemical industry,medical and health,food industry,and industrial and agricultural production.n-Propanol is also widely used.The reduction of carbon dioxide to alcohol may provide sustainable,valuable fuel for industrial and energy demand.Among a variety of conversion approaches,electrochemical methods have a number of advantages.1)electroreduction is generally undertaken at room temperature with the possibility of minimizing chemical consumption by the recycling of electrolytic components;2)the use of renewable energy sources as the electricity force to drive the conversion,which means no additional CO₂ production:from this specific viewpoint,the method can be also considered a renewable energy storage mechanism;3)the electrochemical conversion of CO₂ can be customized to provide a preferred product by selecting suitable electrocatalysts,electrolytes,and applied voltages.In this way CO₂ can be converted electrochemically to several targeted molecules.Therefore,electrochemical reduction of carbon dioxide is a research topic that people are paying more attention to.The reduction of carbon dioxide to alcohol is a hot topic of research.The selection of catalysts is widely in electrochemical reduction of carbon dioxide.It is generally divided into homogeneous catalysts and heterogeneous catalysts.Homogeneous catalysts are usually organic or metal-organic molecules which are dissolved in the electrolyte;heterogeneous catalysts are usually new inorganic catalysts include metals,transition metal oxides,carbon materials,and so on.In terms of metal electrode materials,metal copper is also widely studied,although copper has low selectivity and poor stability.Therefore,it is very important to modify catalyst.Therefore the research work of this thesis is based on copper-based materials.?1?Preparation of CuO and its electroreduction of carbon dioxideUsing the method of calcining intermediates,CuO materials were prepared.The synthesized materials were characterized by XRD,SEM,surface roughness,carbon dioxide adsorption,and the prepared CuO materials were used for the electrochemical reduction of carbon dioxide.Through the exploration of material preparation conditions,it was found that the calcination temperature can affect the catalytic performance of the catalyst.Under normal temperature and pressure,electroreduction of carbon dioxide was achieved on CuO prepared by the calcination method,with total faradaic efficiency of 41.0%for ethanol and n-propanol.?2?Preparation of copper-based MOFs material Cu₃?BTC?₂ and its electroreduction of carbon dioxideCu₃?BTC?₂ material was prepared and characterized by XRD,SEM,FT-IR and EDX mapping.Electrocatalytic reduction of carbon dioxide was carried out on this materials under normal temperature and pressure.The products detected were ethanol and n-propanol.The total faradaic efficiency of the alcohol product reached 49.0%.In addition,the preliminary investigation of the calcination of Cu₃?BTC?₂ material reveals that the copper-based MOFs will become CuO after calcined in air.The CuO material prepared by this method was found to exhibit good catalytic activity for the electroreduction of carbon dioxide.The total faraday efficiency of ethanol and n-propanol reached 55.0%.