Electrocatalytic Reduction Of CO₂ By Mo-Bi BMC In Aminoimidazole Ionic Liquid Electrolyte

Carbon dioxide emissions now reached unprecedented levels,caused many adverse environmental problems,such as global warming,desertification ocean acidification,etc.In recent decades,people has been committed to the CO₂capture using?CCU?research and development to improve energy utilization efficiency is one of the most efficient CO₂ emission reduction approach.The electrochemical method has been widely accepted for its high efficiency,mild and controllable nature,as well as its remarkable features of avoiding potential environmental pollution caused by redox reagents used in common chemical reactions.Therefore,it has practical significance in the organic recycling of carbon dioxide.The ionic liquid has advantages of high electrical conductivity,low vapor pressure,high thermal stability,and chemical stability.The research on the electrochemical reduction of CO₂ with ionic liquid as the electrolyte system has been widely recognized by the academic community.In this study,it is believed that the ionic liquid with an amine side chain is expected to enhance the binding ability of the ionic liquid to CO₂.The reduction process plays a more significant role in promoting the catalysis.In this way,the research on the electrochemical reduction behavior of CO₂ was carried out.The specific research contents and conclusions are as follows:?1?Preparation of Molybdenum Sulfide Bimetallic Catalyst?Mo-Bi BMC?In this thesis,a hydrothermal method was used to prepare molybdenum ruthenium ruthenium bimetallic catalyst?Mo-Bi BMC?.The crystal structure and surface element composition of the catalyst were physically characterized by XRD,SEM,TEM,XPS and other physical characterization techniques.Part of the non-spherical layered structure particles,the particle size is about 50-150nm,the layers are composed of MoS₂,Bi₂S₃,and there was an interaction between MoS₂ and Bi₂S₃.?2?Effect of H₂O content on electrochemical reduction behavior of CO₂ in H₂O-[Emim]BF₄/[NH₂-emim]BF₄ binary electrolyte systemThe influence of H₂O content in the binary electrolyte system H₂O-[Emim]BF₄/[NH₂-emim]BF₄ on the electrochemical reduction behavior of CO₂ was determined by cyclic voltammetry.Cyclic voltammetry results showed that in the H₂O?x%?-[Emim]BF₄ electrolyte system,the maximum reduction peak current density increased first and then decreased with the increased of water content,H₂O?40%?-[Emim]BF₄ had the maximum reduction peak current density.In the H₂O?x%?-[NH₂-emim]BF₄ electrolyte system,the initial reduction potential did't change significantly with the increase of water content,and the maximum reduction peak current density increased first and then decreased,H₂O?40%?-[Emim]BF₄ had the maximum reduction peak current density.?3?Effect of MeCN content on electrochemical reduction behavior of CO₂in MeCN-H₂O-[Emim]BF₄/[NH₂-emim]BF₄ ternary electrolyte systemTheinfluenceofMeCNcontentin MECN-H₂O-[Emim]BF₄/[NH₂-emim]BF₄ ternary electrolyte system on the electrochemical reduction behavior of CO₂ was tested by cyclic voltammetry.Theresultsofcyclicvoltammetryshowedthatinthe MeCN?x%?-H₂O?40%?-[Emim]BF₄ electrolyte system,the reduction peak current density increased with the increase of MeCN content,In MeCN?20%?-H₂O?40%?-[Emim]BF₄ electrolyte had the largest reduction peak current density and the fastest electrochemical reduction rate of CO₂;In the MeCN?20%?-H₂O?100%?)-[NH₂-emim]BF₄ electrolyte system,the initial reduction potential did not change significantly with the increase of MeCN content,and the peak current density increased first and then decreased,MeCN?20%?-H₂O?100%?-[NH₂-emim]BF₄ electrolyte had the highest current density and CO₂ electrochemical reduction rate was the fastest.?4?Comparison of electrochemical reduction behavior of CO₂ in[NH₂-emim]BF₄ and[Emim]BF₄ electrolyte systemsComparing[Emim]BF₄ and[NH₂-emim]BF₄ as supporting electrolytes for CO₂ electrochemical reduction performance,it was found that the cyclic voltammetry test and its corresponding Tafel curve showed that in the[NH₂-emim]BF₄ electrolyte system,the reduced peak current densities were larger than those in the corresponding[Emim]BF4 electrolyte system,and the peak current density in the electrolyte system containing MeCN is larger than that in the system without MeCN.