Electrocatalytic Systems for NO_x Valorization in Organonitrogen Synthesis

Abstract

Inorganic nitrogen oxide (NOx) species, such as NO, NO2, NO3−, NO2− generated from the decomposition of organic matters, volcanic eruptions and lightning activated nitrogen, play important roles in the nitrogen cycle system and exploring the origin of life. Meanwhile, excessive emission of NOx gases and residues from industry and transportation causes troubling problems to the environment and human health. How to efficiently handle these wastes is a global problem. In response to the growing demand for sustainability, scientists are actively pursuing sustainable electrochemical technologies powered by renewable energy sources and efficient utilization of hydrogen energy to convert NOx species into high‐value organonitrogen chemicals. In this minireview, recent advances of electrocatalytic systems for NOx species valorization in organonitrogen synthesis are classified and described, such as amino acids, amide, urea, oximes, nitrile etc., that have been widely applied in medicine, life science and agriculture. Additionally, the current challenges including multiple side reactions and complicated paths, viable solutions along with future directions ahead in this field are also proposed. The coupling electrocatalytic systems provide a green mode for fixing nitrogen cycle bacteria and bring enlightenment to human sustainable development.

Nitrogenous Intermediates in NOx‐involved Electrocatalytic Reactions

“…[64] The Li group illustrated the feasibility of obtaining amino acids with an impressive 93 % purity using a straightforward freeze-drying method. [19,22,40,65] Additionally, the isolation of cyclohexanone oxime achieved with a remarkable 95 % yield through simple separation and steam drying. [18] Separation technologies can significantly contribute to the practicality of electrocatalytic reactions involving NO x .…”

“…Diversifying electrochemical routes, exploring coupling reactions, and leveraging multicomponent catalysts holds the potential to achieve selective and efficient NO x reduction. [65,68] The innovations in reaction pathways will enable the synthesis of value-added nitrogenous compounds from NO x , contributing to sustainable chemical synthesis. In addition, the development of ex-cell processes coupled with electrochemical processes can effectively expand the application of NO x electric reduction.…”

Ultrafine Iridium Nanoparticles Anchored on Co-Based Metal–Organic Framework Nanosheets for Robust Hydrogen Evolution in Alkaline Media

“…Hydrogen (H 2 ), as a clean energy carrier with high energy density, has garnered significant attention for producing high-purity hydrogen fuel through electrocatalytic water splitting. − While platinum-based catalysts demonstrate remarkable efficiency in alkaline hydrogen evolution reaction (HER), their widespread implementation is hindered by limited resources and poor activity for water splitting. − …”

Recent research progress on building C–N bonds via electrochemical NOx reduction

“…As this area is developing quite rapidly, this minireview does not aim to provide a complete compilation of publications (readers may refer to other reviews to get a comprehensive understanding of this area). 37,38 Instead, we will first give a brief summary of building C-N bonds by electrochemical NO x RR, and then mainly focus the most recent reports in this area in the last two years, and summarize the main challenges and emerging opportunities to develop more efficient NO x RR systems to drive electrosynthesis of organonitrogen compounds. The first electrocatalytic C-N coupling process was demonstrated in 2019 by Jiao's group.…”