Direct Fixation Of Carbon Dioxide To Multiple-Carbonyl Organic Compound By Catalytic Electrolysis And The Investigation Of Electrocatalytic Syntheses On Nanocrystalline TiO₂ Electrode

The paper is composed of the following three parts:First, electrolytic Fixation of Carbon Dixiode to mutiple-carbonyl organic compound was studied by directly catalytic electrolysis and electrocatalytic mechanism was investigated. The precursor Ti(OEt)4 was prepared by anodic dissolution of metallic titanium in absolute ethanol and directly hydrolyzed to prepare Ti/nano-TiO2 by a sol-gel process. Electrochemical activities of Ti/nano-TiO2 electrode in the reduction of CO2 were studied by electrochemically transient methods. The fixation of CO2 was investigated by controlled-potential electrolyses on Ti/nano-TiO2 electrode. Analysis and characterization of the electro-reduced product of CO2 were carried out by using HPLC, UV, IR, MS,1HNMR and 13CNMR methods. According to the analysis of the four spectra of the product, molecular weight is determined to be 282, and molecular formula is C12H10O8. The product is a conjugated multiple-carbonyl organic compound and it is a new compound, which hasn't been searched in CA formula index.Second, indirect electrocatalytic synthesis of o-Aminophenol on Nanocrystalline TiO2 Electrode. Electrocatalytic activities and selectivity of o-Nitrophenol in acidic media were studied by electrochemical method. And heterogeneous electrocatalytic synthetic mechanism of o-Aminophenol was investigated on Nanocrystalline TiO2 Electrode. Under optimum conditions the yield and current efficiency of synthetic o-Aminophenol can reach 94.7% and 91.4% respectively, with product purity being 99.1%.Finally, heterogeneous electrocatalytic synthesis of p-Aminobenzoic acid on Nanocrystalline TiO2 Electrode. Electrocatalytic activities and selectivity of p-Nitrobenzoic acid both in acidic and alkaline solutions were studied by electrochemical method. And in alkaline media heterogeneous electrocatalytic synthetic mechanism was investigated on Nanocrystalline TiO2 Electrode. Under optimum conditions the yield and current efficiency of synthetic p-Aminobenzoic acid can reach 96.7% and 92.8% respectively, with product purity being 99.4%.