Preparation Of Porphyrin With Disulfide Bond And Electro-catalytic Application Research

Looking for a cheap and environmentally friendly catalyst for the electro-catalytic reduction of oxygen and hydrogen peroxide has become a problem in practical applications such as biological analysis and clean energy. Metal prophyrin derivatives were synthesized from hemin, because of their higher conjugated structure and chemical stability, and their closer relationship to monooxygenase P-450, theoretically, metal porphyrin derivatives have higher catalytic reduction activity and selectivity for oxygen and hydrogen peroxide. Usually the assembled electrode prepared by the interaction between metal porphyrin and metal surface (e.g.Au) could realized the electro-catalytic reduction of oxygen and hydrogen peroxide. Metal porphyrin compound containing a disulfide bond could form a stable covalent bond through a disulfide bond (-S-S-) and the gold surface to obtain a highly ordered and thermodynamically stable metal porphyrin self-assembled electrode, which showed a huge advantage in electrochemical sensors and electrochemical catalytic applications. In the paper, hemin as raw materials, we designed and synthesized two metal porphyrins containing the disulfide bond which were used as catalyst for the electro-catalytic reduction of oxygen and hydrogen peroxide. This dissertation includes the following content:1. Co(Ⅱ)-MPDTEP was prepared from hemin by a six-steps reaction including deferrization, esterification, catalytic hydrogenation, hydrolyzation, condensation and complexation; Co(Ⅱ)-PDTEP was prepared from hemin by a four-steps reaction including taking off vinyl, deferrization, condensation and complexation. The synthetic experimental conditions of these two compounds were optimized and the target products were characterized with1H NMR, MS and IR.2. Gold electrodes modified by Co(Ⅱ)-MPDTEP was prepared by self-assembly of disulfide on gold, the properties of the modified electrodes were investigated by FT-IR, XPS, as well as electrochemical methods. Taking the Co(Ⅱ)-MPDTEP modified electrode for the electro-catalytic reduction of oxygen, the results showed that the Co(Ⅱ)-MPDTEP modified gold electrode had good electro-catalytic reduction effect of oxygen, could not only greatly facilitate the electron transfer rate, but also pointed to a surface-controlled process by a four-electrons reaction, could catalyze oxygen reduction to water.3. Gold electrodes modified by Co(Ⅱ)-PDTEP was prepared by self-assembly of disulfide on gold, the properties of the modified electrodes were investigated by FT-IR and electrochemical methods. Taking the Co(Ⅱ)-PDTEP modified electrode for the electro-catalytic reduction of hydrogen peroxide, the results showed that the Co(Ⅱ)-PDTEP modified gold electrode had good electro-catalytic reduction effect of hydrogen peroxide, could catalyze hydrogen peroxide reduction to water.