Promoting Ampere-Level Nitrate Reduction to Ammonia Through Strong Oxide-Oxide Interaction
Haitao Xu1,2, Yang Yang3, Ali Han3
1Laboratory of Advanced Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, State Key Laboratory of Porous Materials for Separation and Conversion, Fudan University, Shanghai, 200433, P.R. China.
Angewandte Chemie (International Ed. in English)
|August 7, 2025
Summary
This study developed a novel cobalt oxide/copper oxide catalyst for efficient electrochemical nitrate reduction to ammonia. This process removes wastewater pollutants while producing valuable ammonia, showcasing a sustainable catalytic system.
Area of Science:
- Materials Science
- Electrochemistry
- Environmental Engineering
Background:
- Nitrate pollution in wastewater poses environmental risks.
- Electrochemical reduction of nitrate to ammonia is a sustainable solution.
- Developing efficient, durable, and cost-effective catalysts is crucial.
Purpose of the Study:
- To develop a high-performance catalyst for electrochemical nitrate reduction to ammonia.
- To investigate the role of oxide-oxide interactions in enhancing catalytic activity.
- To provide a framework for designing advanced catalytic systems.
Main Methods:
- Synthesized cobalt oxide (Co3O4) nanoparticles on copper oxide (CuO) nanosheets (Co3O4@CuO).
- Evaluated the catalyst's performance for nitrate electroreduction to ammonia.
- Conducted mechanistic studies to understand the reaction pathway and interactions.
Main Results:
- The Co3O4@CuO catalyst achieved 93.4% ammonia Faradaic efficiency at 2500 mA cm-2.
- A strong oxide-oxide interaction between Co3O4 and CuO was observed.
- This interaction effectively regulated nitrite adsorption and hydrogenation, enhancing ammonia yield and selectivity.
Conclusions:
- The Co3O4@CuO catalyst demonstrates excellent performance for nitrate-to-ammonia electroreduction.
- Strong oxide-oxide interactions are key to optimizing the catalytic pathway and selectivity.
- This approach offers a promising strategy for wastewater remediation and ammonia synthesis.
Keywords:
Ampere‐level nitrate reductionElectrocatalystsElectrochemical ammonia synthesisOxide–oxide interactionMore Related Videos
Related Concept Videos
01:29Preparation of Amines: Reduction of Oximes and Nitro Compounds
4.0K
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
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,...
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,...
4.0K
01:371° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
4.0K
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
4.0K
01:261° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
3.5K
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
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...
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...
3.5K
01:202° Amines to N-Nitrosamines: Reaction with NaNO2
4.6K
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
4.6K
00:55Nitriles to Amines: LiAlH4 Reduction
3.8K
Nitriles are reduced to amines in the presence of strong reducing agents like lithium aluminum hydride through a typical nucleophilic acyl substitution. The reaction requires two equivalents of the reducing agent. The reducing agent acts as a source of hydride ions.
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
3.8K
01:22Inorganic Nitrogen Assimilation
106
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...
106