A preparation method of Cu-C-N metal-organic framework electrocatalyst for the reduction of nitrate to ammonia

Abstract

The invention relates to the field of catalyst preparation. Aiming at the problem of low catalytic efficiency of existing nitrate-to-ammonia-related catalysts, a method for preparing Cu-C-N metal-organic framework electrocatalysts for reducing nitrate to ammonia is disclosed, comprising : Dissolving 2-methylimidazole in methanol solution to form the first solution; dissolving zinc nitrate hexahydrate and copper acetylacetonate in methanol solution to form the second solution; adding the second solution to the first solution and ultrasonically forming a suspension , transfer the suspension into the reaction kettle, and after constant temperature reaction, cool to room temperature to obtain a dark blue precipitate; wash the collected dark blue precipitate with absolute ethanol and centrifuge, and dry in a vacuum to obtain the precursor ; Vacuum calcination of the precursor to obtain the final product. Due to the high one-dimensional structure, rich micropores and large specific surface area of ​​the core / shell structured nanoparticles, the prepared catalysts have higher electrocatalytic activity in electrochemical workstations.

Description

technical field [0001] The invention relates to the field of catalyst preparation, in particular to a preparation method of a Cu-C-N metal-organic framework electrocatalyst used for reducing nitrate to ammonia. Background technique [0002] The Haber-Bosch process enables the large-scale production of ammonia, with typical yields of less than 200 mmol gcat for this industrial nitrogen reduction reaction (NRR) -1 h -1 . This process is energy-intensive because it is carried out at high temperatures of 400–600 °C, and a more sustainable method for ammonia production is water-based electrocatalytic NRR under ambient conditions. However, these reaction rates and partial current densities are usually less than 10 mmol gcat each -1 h -1 and 1mA cm -2 , the N≡N bond breaking of nitrogen needs 941kJ / mol, while the energy of nitrate decomposing into deoxidized state is much lower, only 204kJ / mol. From an energetic point of view, it is very interesting to explore the electrocata...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims to overcome the problem of low catalytic efficiency of existing nitrate-to-ammonia-related catalysts, and provides a method for preparing Cu-C-N metal-organic framework electrocatalysts for reducing nitrate to ammonia. The prepared Cu-C-N metal-organic Due to the high one-dimensional structure, rich micropores and large specific surface area of ​​the frame-structure nanomaterial electrocatalyst, it can produce higher electrocatalytic activity in the electrochemical workstation, and has great potential in the field of electrocatalysis. Wide application prospects; the synthetic method of the present invention has the characteristics of simple process, low energy consumption, mild conditions and good product appearance, and is suitable for large-scale production and application

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