Synthesis And Properties Of Surface- And Interface-Modified Metalloporphyrin Composites

The upsurge and high demand of earth's resources,such as fossil fuels have become a matter of concern to the environmental engineers as a result of its associated high levels of pollution.This has necessitated environmental engineers to find a cheap and clean alternative source of energy to fossil.Hydrogen,as a clean and efficient energy source,is favored by the vast number of scientific researchers.At present,molecular hydrogen has received wide and vast attention since it involves electrocatalytic decomposition of water to obtain energy.Research on metal porphyrins derivatives have shown their effectiveness in homogeneous hydrogen evolution and oxygen reduction,but there are still many limitations in their use in heterogeneous phase.Therefore,the research on how to apply catalysts to heterogeneous phase is also a hot topic at present.In this paper,through the design and synthesis of a variety of compounds,metalloporphyrin derivatives were tested and applied in heterogeneous solutions by different modification methods.?1?We designed and synthesized a cobalt porphyrin containing phenanthrene ring.Introducing the phenanthrene ring on the porphyrin was to improve the pi conjugations of the system which could enhance its performance via electron transport.The large?conjugation of the entire compound in addition enhances?-?interaction between the porphyrin and the carbon material,thereby enhancing the interaction between the metal porphyrin active center and the carbon material.At the same time,the stability of the entire catalytic system is enhanced,so that it can maintain a long-lasting high catalytic activity in a strong acid solution.?2?The paper studies the metal iridium corrole modified by the axial pyridine-thio ligand,forming a stable"Au-S"covalent bond on the surface of the gold electrode through the axial pyridine-thio group,thereby forming a stable catalytic system.Electrocatalytic performance of the corrole molecule on the surface of the gold electrode was tested towards ORR and HER.The result obtained shows the efficiency and importance of axial ligands in electrocatalytic systems.It is prudent to state the our catalyst could serve bifunctional purposes due to its high performance in terms of ORR and HER.?3?A class of metal platinum pyridine complexes containing a freebase of corrole is reported.Due to the changes at the position of the catalytic center,the electron transmission path between the catalytic center and the carbon material is believed to have changed,thereby increasing the electron transmission speed.The purpose of improving the electrochemical catalytic performance of metal platinum pyridine complex was achieved.It's Tafel slope is 59 mV/dec,which is only a little higher than the current commercial Pt/C catalyst which is 35 mV/dec.?4?A₃ cobalt corrole containing different groups were synthesized.Mixtures of varied volumes of THF solution and water were prepared and used to electrochemical test the recrystallization behavior of corrole materials.The electrochemical catalytic performance of the corrole molecule is adjusted by changing the morphology of the corrole in the loading system.Graphene was used as the carbon matrix to modify the surface of the glassy carbon electrode,and the electrocatalytic performance of the corrole after the recrystallization strategy was explored.The results showed that using the recrystallization strategy can positively shift the initial potential of the cobalt corrole electrochemical hydrogen evolution about 0.1 V.In summary,we have illustrated that changes in surface modification methods changes the electron transport route of surface catalysis of metal porphyrins and thus lays a theoretical and experimental basis for improving electrochemical performance of catalysts materials.