Heterointerface-Enhanced Active Hydrogen Generation in Ru/RuOx/CNTs for Nitrate Reduction to Ammonia at Low
Huijun Ren1, Ziwen Shen1, Changgen Cheng1
1School of Nanoscience and Materials Engineering, Henan University, Zhengzhou, 450046, China.
Small (Weinheim an Der Bergstrasse, Germany)
|September 5, 2025
Summary
New Ru/RuOx/CNTs catalysts efficiently convert nitrate to ammonia, a key fertilizer, with high yields. This electrocatalytic process offers a sustainable pathway for producing valuable chemicals from waste nitrate under solar power.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Nitrate contamination poses environmental risks.
- Efficient conversion of nitrate to valuable products like ammonia is crucial.
- Developing advanced catalysts for electrochemical nitrate reduction is an active research area.
Purpose of the Study:
- To synthesize and characterize Ru/RuOx/CNTs heterostructured materials.
- To investigate the electrocatalytic performance of these materials for nitrate reduction.
- To explore the application of these catalysts in a solar-powered system for ammonia and fertilizer production.
Main Methods:
- In situ synthesis of Ru/RuOx/CNTs heterostructures.
- Electrochemical nitrate reduction experiments.
- Differential electrochemical mass spectrometry (DEMS) and Electron Paramagnetic Resonance (EPR) for mechanistic studies.
- Fabrication and testing of a solar-powered nitrate-hydrazine reforming electrolysis cell.
Main Results:
- Ru/RuOx/CNTs exhibited excellent catalytic activity for nitrate reduction to ammonia with high Faradaic efficiency (>90%).
- Achieved ammonia production rate of 1.16 mmol h⁻¹ cm⁻² at low overpotentials (0.25-0 V vs RHE).
- Demonstrated bifunctional catalytic activity in a solar cell powered electrolysis, producing 4.7 g of struvite fertilizer.
Conclusions:
- The Ru─RuOx heterostructure is key for active hydrogen dissociation and efficient nitrate-to-ammonia conversion.
- The developed electrocatalytic system offers a sustainable method for converting nitrate into fertilizer using solar energy.
- These findings guide the design of advanced heterostructured materials for nitrate conversion.
Keywords:
Ru/RuOx/CNTs heterostructureammonia synthesisnitrate‐hydrazine reformingsolar energy to chemical energystruviteMore 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
01:261° 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
01:371° 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
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
02:50Catalysis
27.5K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
27.5K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.4K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.4K