Related Experiment Video
Updated: Jan 7, 2026
09:50
Electrochemically and Bioelectrochemically Induced Ammonium Recovery
Published on: January 22, 2015
13.1K
Stabilizing calcium nitride for efficient, long-term electrochemical ammonia synthesis
Ishita Goyal1, Hasiya Najmin Isa1, Vamsi Vikram Gande1
1Department of Chemical Engineering, University of Illinois, Chicago, IL 60607.
Summary
Researchers developed a stable electrochemical system for ammonia synthesis using calcium-mediated nitrogen fixation. This innovation enhances gas-liquid stability and reaction kinetics, paving the way for efficient ammonia production.
Area of Science:
- Electrochemistry
- Materials Science
- Chemical Engineering
Background:
- Electrochemical ammonia synthesis via calcium-mediated nitrogen fixation shows promise but faces challenges.
- Key limitations include unstable gas-liquid interfaces, slow hydrogen oxidation reaction (HOR) kinetics, and unstable calcium nitride intermediates.
Purpose of the Study:
- To address barriers in calcium-mediated electrochemical nitrogen fixation.
- To enhance HOR kinetics, improve solvent stability, and optimize gas-liquid mass transport for ammonia synthesis.
Main Methods:
- Introduced a high surface-area Ni-based anode to improve HOR kinetics and reduce solvent oxidation.
- Replaced tetrahydrofuran with dimethoxyethane (DME) for enhanced chemical stability.
- Developed a tailored flow cell configuration for improved mass transport and intermediate stabilization.
Main Results:
- Achieved a Faradaic efficiency (FE) of 34.35 ± 1.76% in short-term tests and sustained ~20% FE over 56 hours.
- Demonstrated robust ammonia production at elevated current densities (~219 mA cm⁻² at ~29% FE) due to improved interface stability.
- Provided direct evidence of stabilized calcium nitride formation using in-situ Raman and X-ray photoelectron spectroscopy.
Conclusions:
- The study establishes critical mechanistic understanding for calcium-mediated electrochemical nitrogen fixation.
- Highlights the importance of solvent stability and anode composition for sustaining reactive intermediates.
- Provides design principles for stable, efficient, and selective ammonia synthesis systems.
Related Concept Videos
01:371° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
4.7K
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.
4.7K
01:30Preparation of Amines: Alkylation of Ammonia and Amines
4.5K
Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines along with a quaternary ammonium salt through successive SN2 reactions. This process of making the quaternary salt through the direct alkylation method is called exhaustive alkylation.
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
4.5K
01:22Inorganic Nitrogen Assimilation
421
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...
421
00:55Nitriles to Amines: LiAlH4 Reduction
4.5K
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...
4.5K