Preparation method for Fe-N-C catalytic material with controllable edge active sites

Abstract

The invention discloses a preparation method for an Fe-N-C catalytic material with controllable edge active sites. Under the premise of keeping the original MOF (metal-organic framework) morphology, the preparation method which adopts the method of in-situ embedded molecular aggregate and then high-temperature pyrolysis is intended to change the dosage of small molecules to regulate the frameworkpore structure and the degree of C-N bond rupture, and realizes the control of edge active site number and chemical environment around a single atom for the first time, thus achieving more excellent electrochemical properties. The method adopts an appropriate dosage of small molecules to obtain a ORR (oxygen reduction reaction) catalyst with the specific surface area of 1392.91m<2> / g, the half-wave potential in 0.1M KOH can reach 0.915V(vs.RHE), and the catalytic performance of the Fe-N-C catalytic material is better than the catalytic performance of commercial platinum-carbon catalyst and similar materials. Therefore, the method realizes atom-level active site control and molecule-level structure control, reference significance is provided for the reasonable design of high-performance single-atom catalysts.

Description

technical field [0001] The invention belongs to the technical field of nanometer material preparation, and in particular relates to an Fe-N-C material with controllable edge active sites, which can be applied to electrocatalytic oxygen reduction reaction. Background technique [0002] The development and utilization of fuel cells is an important way to solve the energy crisis and alleviate environmental pollution. However, as an essential cathode reaction for fuel cells, the oxygen reduction reaction (ORR) still requires expensive and limited storage of Pt-based catalysts, which greatly limits the commercial application of fuel cells. Therefore, inexpensive and abundant non-precious metal catalyst M-N-C materials have attracted extensive attention due to their excellent catalytic activity in ORR. Among them, the atomically dispersed M-N-C active sites are characterized by their unique electronic structures and efficient O 2 Adsorption and reduction efficiency, showing very...

AI Technical Summary

Problems solved by technology

However, if a single metal site is embedded in the MOF channel, it is not only difficult to fully expose the internal catalytic active site, but more importantly, it is difficult to precisely adjust the coordination of the catalytic site by using N-containing MOF ligands to coordinate with the metal. bit environment, improving the electronic structure of the active center

Therefore, it is still very challenging to achieve molecular-level dispersion and electronic structure regulation in M-N-C catalysts, and synergistically realize the precise controllability of the overall macroscopic physical structure.

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