FT-IR Spectroelectrochemistry Study On The Reduction Of CO₂at Different Metal Electrodes Interface

In this paper, the background and developing status of the reduction of CO2were firstly introduced. The possible mechanisms of the CO2reduction in different electric catalysts and electrolyte were concluded in detail in this paper. Combined with the electrochemical, the best conditions of the reduction of CO2were selected.Cyclic voltammetry (CV) and in-situ FTIR spectroelectrochemistry cyclic voltabsorptometry (CVA) techniques were utilized to study the electron transfer mechanism of the reduction of CO2on the gold electrode and lead electrode, and various species changes of these compounds among their electrochemical redox process were described. Finally, the graphene oxide modified glassy carbon electrode was prepared and used in the reduction of CO2.The main work results summed up as follows:1. The electrochemical cyclic voltammetry (CV) method was used for investigating the reduction of CO2on gold and lead surface. The results showed that, CO2reduction peak can be observed in propylene carbonate (PrC) including tetrabutyl ammonium perchlorate (TBAP) as electrolyte.When the scanning speed was2mv/s,the reduction of the peak in the gold surface appeared in the potential of1.8V.2. Electrochemistry and FT-IR spectroelectrochemistry methods were used for investigating the reduction of CO2on Au and Pb surface in propylene carbonate (PrC) including tetrabutyl ammonium perchlorate (TBAP) as electrolyte.By using the infrared spectroelectrochemistry cyclic voltabsorptometry (CVA), it is found that both of them have the same changes, with the decrease of CO2, the CO and CO32-were produced. Combined with the results obtained from electrochemistry and FT-IR spectroelectrochemistry, the electrochemical reduction mechanism of CO2in the non-aqueous media is proposed:CO2was generated firstly, and then CO2-reduced to CO by two pathways. One is electrochemically reduced to CO directly, the other is CO2radicals reaction with CO2to generate C2O4--, then leading to formation of CO and CO32-. Both of them carried out at the same time the former is reversible process. 3. Graphene sheets were successfully stripped out from bulk graphite utilizing modified Hummers method. The graphene oxide solution was dropped on the surface of pre-treated glassy carbon electrode so as to acquire graphene oxide modified electrode and then the modified electrode was electrochemically reduced by introducing cyclic voltammetry technology in an acidic phosphate buffer solution. This electrode was used for reduction of CO2. The results was different from the metal electrodes’.It can change the mechanism on the metal electrode surface effectively. Electrochemical products contained formic acid. Specific reduction mechanism needs to be further textual research.