Optical Detection Methods For The Electrochemical Reduction Of Carbon Doxide To Formic Acid

Carbon dioxide (CO2) mitigation is an important scientific problem, and it has become a hot issue of the whole world. Co verting CO2 to organic chemical material using renewable energy, and recyling carbon resources to reduce its dependence on fossil fuels, is one of the important technical ways for carbon dioxide mitigation. Formic acid (HCOOH) is a kind of important organic chemical raw materials, and it has been applied broadly in the field of pharmaceutical industries, chemical industries, pesticide industries, rubber industries and other neighborhood. In recent years, many researchers try to use renewable energy (wind power, photovoltaic power, tidal power, etc.) as the electrolytic power to convert CO2 into HCOOH with the electrochemical reduction of CO2. However, reports of the optical detection method for electrolytic product are less common. Therefore, this thesis has carried out the following research work in view of optical detection method for CO2 electroreduction product:Using the underlying theory of holography interference to explore the digital holographic detection method for HCOOH.We made 17 groups of HCOOH solution with different concentration, which were measured with digital holography method. Hologram of high pure water is used as standard in the experiment, and it is subtracted by the hologram of HCOOH solution with different concentrations. So we can do quantitative analysis of HCOOH solution by observing the change of fringes in the reconstruction image of the hologram.Using chromatographic analysis to research the refraction detection of HCOOH. The relevant experiment found that only with the mixed solution of 93 % 0.1 mol/L KH2PO4 (monopotassium phosphate) and 7% CH3CN (acetonitrile) as mobile phase, can we obtained the best separation results of electroreduction products with the ODS-BP (reversed-phase C18) as stationary phase.17 groups of HCOOH solution with different concentration are prepared, and collecting chromatogram of HCOOH solution with different concentration under the above test condition, do quantitative analysis of HCOOH solution with different concentrations through the standard curve method, and the results show that the minimum detectable level of HCOOH solution is 0.03 mol/L.Studying the electrochemical reduction of CO2 on gold and tin electrode in potassium bicarbonate aqueous solution. The experiment results show that the main product is CO, and no liquid product generated in the electrolytic process on Au electrode. In addition, the result of the experiments also reveals that the electrocatalytic activity of cathode material is falling rapidly during the electrochemical reduction.However, the main electrolytic product is HCOOH on Sn electrode, and electrode deactivation also occurs.Qualitative and quantitative analysis is done to the electroreduction products of carbon dioxide on Sn electrode with digital holography and the refraction detection, the results show that the digital holography testing for the whole fringes appear in the reconstruction image of the hologram of the electrolyte with mixture of KHCO3, HCOOH and H2O. Therefore, digital holography is difficult to make qualitative and quantitative analysis for a composition of the mixture. And refractive index test results show that the qualitative and quantitative analysis is feasible for a single solvent solution or mixture.