Related Experiment Video
Updated: Sep 20, 2025

Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
A vacancy engineered MnO2- electrocatalyst promotes nitrate electroreduction to ammonia.
Guohui Wang1, Peng Shen1, Yaojing Luo1
1School of Materials Science and Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China. chuk630@mail.lzjtu.cn.
Researchers developed oxygen-vacancy-rich MnO2 nanosheets for efficient nitrate reduction reaction (NO3RR) to produce ammonia (NH3). This breakthrough offers a sustainable pathway for ammonia synthesis with high yield and stability.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Nitrate reduction reaction (NO3RR) is a promising sustainable route for ammonia (NH3) production.
- Developing high-performance electrocatalysts for NO3RR remains a significant challenge.
Purpose of the Study:
- To construct oxygen vacancies (OVs) on MnO2 nanosheets to enhance their electrocatalytic activity for NO3RR.
- To investigate the performance and stability of OV-rich MnO2 for NH3 synthesis.
Main Methods:
- Synthesis of OV-rich MnO2 nanosheets.
- Electrochemical evaluation of NO3RR performance, including ammonia yield and faradaic efficiency.
- Density Functional Theory (DFT) calculations to elucidate the reaction mechanism.
Main Results:
- OV-rich MnO2 nanosheets achieved a high NH3 yield of 3.34 mg h-1 cm-2 at -1.0 V vs. RHE.
- An excellent faradaic efficiency (FE) of 92.4% for NH3 was obtained at -0.9 V vs. RHE.
- The material demonstrated outstanding stability during the electrochemical process.
Conclusions:
- Oxygen vacancies on MnO2 act as active sites, facilitating nitrate adsorption and dissociation.
- OVs reduce hydrogenation energy barriers, promoting efficient NO3- to NH3 conversion.
- OV-rich MnO2 is a highly promising electrocatalyst for sustainable ammonia production via NO3RR.
Related Concept Videos
Preparation of Amines: Reduction of Oximes and Nitro Compounds
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
Electrophilic Aromatic Substitution: Nitration of Benzene
2° Amines to N-Nitrosamines: Reaction with NaNO2
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
Metabolism of Chemolithotrophs

