Preparing method of carbon-loaded monoatomic metal nitrogen-containing compound oxygen reduction catalyst and obtained catalyst

Abstract

The invention provides a preparing method of a carbon-loaded monoatomic metal nitrogen-containing compound oxygen reduction catalyst. The method comprises the steps of pre-oxidizing nitrogen-containing biomass at a first high temperature, after a pre-oxidized product is uniformly mixed with a transition metal source and a pore-forming agent, conducting first calcination at a second high temperature in an inert gas atmosphere, after a calcined product is subjected to acid pickling, washing and drying, conducting second calcination again at the second high temperature, and finally, obtaining thecarbon-loaded monoatomic metal nitrogen-containing compound oxygen reduction catalyst. The preparing method has the advantages of being low in raw material cost, simple in preparing technology and the like; the prepared catalyst has the advantages of being high in pH universality, atom utilization rate, catalytic performance and stability, excellent in methyl alcohol resistance and the like, is expected to replace expensive carbon-loaded platinum catalysts, and is about to have a wide application prospect in efficient and cheap large-scale commercialized fuel cells.

Description

technical field [0001] The invention relates to the technical field of electrocatalytic materials and new energy, in particular to a preparation method of a carbon-supported single-atom metal nitrogen-containing composite oxygen reduction catalyst and the carbon-supported single-atom metal nitrogen-containing composite oxygen reduction catalyst prepared by the preparation method catalyst. Background technique [0002] Energy shortage and environmental pollution are major problems that human society is facing urgently. The development of sustainable clean energy and advanced energy conversion technology can provide a good solution to these problems. Among them, the polymer electrolyte membrane fuel cell (PEMFC), which uses hydrogen as fuel, has the advantages of non-toxic, non-polluting, high specific energy, high specific power, etc., and has great application potential in the battery field. Fuel cell vehicles driven by fuel cells are also considered to be an important choi...

AI Technical Summary

Problems solved by technology

However, this type of catalyst still has the following problems: First, there are defects in the catalyst structure. On the one hand, although the prepared catalyst metal exists in the form of single atoms and has a high loading capacity, due to the relatively closed structure, the actual atom utilization rate is low. On the other hand, due to the neglect of the graphitization structure of the carbon support, the catalyst is not resistant to acid and alkali and the electron transport is weak, so the overall catalytic performance is not good; second, the pH universality is low, and the performance in alkaline electrolyte It has excellent catalytic performance, stability and methanol resistance, but it cannot have matching performance under the more practical neutral and acidic electrolytes; third, it is difficult to mass-produce, and the current preparation of carbon-supported transition metal The methods of single-atom catalysts include but are not limited to template method, wet chemical method, atomic layering method, chemical vapor layering method and other methods. Even if high-efficiency catalysts can be prepared, they cannot be prepared on a large scale due to the complexity of the preparation process; the fourth , the cost is high, and the carbon carrier chooses expensive graphene, carbon nanotubes, etc., and the preparation process requires high equipment, etc.

In particular, recent studies reported that by maximizing the construction of M-N x It is an important method to improve the performance of M-N / C catalysts (ACS Catal. 2018, 8, 2824-2832; Adv. Mater. 2018, 1802304; Angew, 2016, 55, 10800) However, how to prepare M-N / C catalysts with 100% atomic utilization is still the most important challenge

Images