The Investigation Towards Synthesis And Electrochemical Carbon Dioxide Reduction Reaction Of Transition Metal Copper And Tin-based Nano Composite Materials

In order to realize the recycling use of excessive emissions of CO₂ from the combustion fossil fuels,we put forward the efficient,environmental protection,simple operation of carbon dioxide reduction reaction（CO₂RR）,which conform to the requirements of the feasibility and the sustainable development strategy of resource recycling.Deactivation,poor selectivity and poor stability of catalysts affected CO₂RR industrialization process.It is of important factor that the reaction mechanism is not comprehend thoroughly,which hinders the development in the face of many scientific challenges.This article mainly studies activity,stability and selectivity of catalyst in the process for CO₂RR in aqueous solution by transition metal Cu and Sn,this two kinds of typical metal catalysts that were modified.The detailed research content about this paper and the results are as follows:（1）We proposed synthesis of HKUST-1 as a precursor by simple hydrothermal method.And we exploited the flower shaped Cu₃P and carbon compounds（Cu₃P/C）with copper-based metal organic framework（HKUST-1）as precursor through sodium phosphate as a source of phosphorus towards phosphatizing treatment in the shielding gas,which has a larger specific surface area and can expose more active site.The structure and morphology characteristics of catalysts also promote the performance of CO₂RR.In the CO₂-saturated solution of 0.1 M KHCO₃,systematic electrochemical characterizations demonstrate the Cu₃P/C nanocomposites are manifested by a faradic efficiency（FE）of 47%for CO production at a lower potential-0.3 V vs.reversible hydrogen electrode（RHE）and compared with contrast samples at the same potential,which shows a higher current density.Furthermore,the asymmetrical-electrolyte Zn-CO₂ cell was built by using the Cu₃P/C as cathode catalyst,demonstrating a remarkable performance with an open-circuit potential of 1.5 V and a power density of 2.6 mW cm^-2(at 10 mA cm^-2).We have synthesized materials showed good catalytic activity,stability and selectivity for the reduction of CO₂ to CO at a low overpotential in numerous Cu base catalyst,meanwhile,the synthesis of sample are more simple and cheaper compared with noble metal Au or Ag catalysts.（2）We choose the cube structure of NaCl and glucose as a template and carbon source,respectively.Synthesized the catalyst material that Sn nanoparticles（average size is about 10 nm）was coated by porous carbon network（marked Sn-CNWs）.Porous structure played a significant role in the reaction rate,the large specific surface area provides more active sites and carbon network structure can improve the electrical conductivity of the material,thereby reducing the resistance.Sn-CNWs can convert CO₂ into HCOOH with the FE of 23.5%at-0.6V.In the catalyst of catalyzing CO₂ to generate liquid products,Sn dominates an important position for obtain liquid phase products among the numerous catalysts.