The Design And Synthesis Of Carbon Catalysts Derived From Bovine Blood

With the progress and development of human society,the awareness of environmental protection of human beings is increasing.Energy conversion devices such as fuel cells are of great significance to achieve green and sustainable development.Oxygen reduction reaction is used as the cathode reaction in fuel cells,metal-air batteries and other devices.The overpotential is high,and the catalyst is needed to accelerate the kinetic process.At present,the reaction still relies on platinum-based noble metal catalysts,and the high cost of noble metals has slowed the development and promotion of fuel cells to a certain extent.Therefore,it is very important to develop high-activity non-noble metal catalysts with low cost.This thesis takes waste animal biomass bovine blood as the precursor and uses its naturally contained organic-inorganic structure to prepare a carbon-based catalyst with excellent oxygen reduction activity and high stability,and to improve the intrinsic activity of the catalyst.The entry point is to optimize the pore structure of the material and increase the number of active sites by adjusting the process parameters in the preparation process.The serum-based metal-free carbon catalyst and the iron and nitrogen co-doped carbon-based oxygen reduction catalyst are prepared for development.Low-cost and high-efficiency non-noble metal catalysts provide broad design strategies and ideas.The important innovative results achieved in our paper are as follows:Separating of bovine blood,using the supernatant bovine serum as the precursor.With its natural inorganic-organic structure,a new type of porous carbon preparation method-template generation method is developed:combining bovine serum powder with metal.After pretreatment with salt,after pyrolysis and acid washing,a carbon material with hierarchical porous structure was successfully prepared,with a specific surface area of 804.89 m2 g-1 and a total pore volume of 0.8841 cm3 g-1.The serum-based carbon is used as a metalfree catalyst to catalyze the oxygen reduction reaction,which is much different with the carbon developed by directly pyrolysis.The catalyst has excellent activity and stability in an alkaline medium,and the half-wave potential can reach 0.88 V,and there is almost no attenuation after 10,000 cyclic scanning.The zinc-air battery assembled from the serum-based carbon also shows better performance than commercial Pt/C,and has a higher maximum power density at a higher current density.Make full use of bovine blood,take red blood cell powder as the precursor,and extract heme with macrocyclic porphyrin structure by glacial acetic acid method;use serum powder as the precursor to prepare porous carbon carrier by the template method.And heat them at high temperature,an all-biomass iron and nitrogen co-doped oxygen reduction catalyst material was ingeniously prepared.The iron-nitrogen doped carbon catalyst has oxygen reduction activity in both acidic and alkaline media.In 0.1 M KOH,the half-wave potential of the catalyst can reach about 0.86 V,and it has a very low hydrogen peroxide yield in an acidic medium,the oxygen reduction reaction occurs according to a reaction path of nearly four electrons.In addition,ammonium molybdate is added in the process to generate a serum-based molybdenum-carbon catalyst by the template method,which has a certain electrochemical hydrogen evolution reaction catalytic performance,and further broadens the application direction of biomass waste preparation of carbon-based catalysts.