Metal-nitrogen carbon material with atomic-scale dispersed metal as well as preparation method and application thereof

Abstract

The invention provides a metal-nitrogen carbon material precursor with atomic-scale dispersed metal. Based on the total weight of the metal-nitrogen carbon material precursor, the content of N is 25 to 35 weight percent and the content of the metal is 0.1 to 1.3 weight percent, wherein the metal is one or more of transition metal or noble metal. The precursor is formed through self-polymerizing aformamide solution of metal salt. After the precursor is roasted in an inert atmosphere at high temperature, a metal-nitrogen carbon material with the atomic-scale dispersed metal is obtained; based on the total weight of the metal-nitrogen carbon material, the content of the N is 4 to 7 weight percent and the content of the metal is 0.3 to 8 weight percent. The precursor and the metal-nitrogen carbon material can be used as an electrochemical catalyst. A preparation method provided by the invention is simple and easy to operate and has economical cost and the preparation efficiency of the atomic-scale dispersed metal-nitrogen carbon material is high.

Description

technical field [0001] The invention belongs to the field of preparation of new materials, and in particular relates to a metal-nitrogen carbon material in which metal is dispersed at the atomic level, its preparation method and its application. Background technique [0002] Atomic-scale dispersed metal nitrogen-carbon composite materials, because of their excellent catalytic performance, high metal component utilization, anti-pollution and high failure, are used in many important electrochemical reactions of energy conversion, such as oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, and carbon dioxide reduction reaction. There are two classic preparation methods: the first is to mechanically mix metal salts, nitrogen sources, and carbon sources, and after high-temperature roasting, use strong acid to remove metal aggregated particles, and use nitrogen to strongly coordinate transition metals. A small amount of atomically dispersed transiti...

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Problems solved by technology

Overall, the first preparation method is extremely inefficient in obtaining atomically dispersed metal-nitrogen-carbon composites, which largely relies on pre-treatment and strict post-processing to ensure the removal of particulate metal components and the removal of atomic-level metal components. Retention of components, and the acid elution rate is greater than 50%, and the content of atomically dispersed metal components remaining in the metal-nitrogen carbon material is extremely low, usually not more than 1wt%

The efficiency of the second material to prepare atomic-scale metal nitrogen carbon materials is much higher than that of the first preparation method, and the content of atomically dispersed metal components remaining in the metal-nitrogen carbon materials can be increased to 1.4wt%-5wt% about, but it is very difficult to increase it. In addition, this method is not suitable for a wide range of industrial production because of its expensive and toxic ligand materials.

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