Electrochemical Synthesis of Ammonia: Recent Efforts and Future Outlook

Abstract

Ammonia is a key chemical produced in huge quantities worldwide. Its primary industrial production is via the Haber-Bosch method; a process requiring high temperatures and pressures, and consuming large amounts of energy. In the past two decades, several alternatives to the existing process have been proposed, including the electrochemical synthesis. The present paper reviews literature concerning this approach and the experimental research carried out in aqueous, molten salt, or solid electrolyte cells, over the past three years. The electrochemical systems are grouped, described, and discussed according to the operating temperature, which is determined by the electrolyte used, and their performance is valuated. The problems which need to be addressed further in order to scale-up the electrochemical synthesis of ammonia to the industrial level are examined.

Towards understanding of electrolyte degradation in lithium-mediated non-aqueous electrochemical ammonia synthesis with gas chromatography-mass spectrometry

“…Lithium-mediated electrochemical ammonia synthesis (LiMEAS) is a promising alternative to the traditional complex thermochemical Haber-Bosch process, [1][2][3][4][5] which predominantly requires high temperatures (400-500 C) and pressures (150-200 bar) coupled with a steam reforming plant for hydrogen (H 2 ) production. 6 On the other hand, the LiMEAS is thermodynamically driven by an electrical potential instead of high temperatures and pressures, and the chemical reactivity of lithium towards nitrogen gas (N 2 ).…”

“…The production of H 2 (for example, water splitting) may overcome some of the issues associated with the traditional Haber-Bosch process, such as the large amount of CO 2 from steam reforming 9 emissions and high cost. 2 A typical LiMEAS cell consists of a noble metal anode e.g. platinum (Pt) and transition metal cathode which does not interact or alloy with lithium (Li) e.g.…”

A Comprehensive Review on the Recent Development of Ammonia as a Renewable Energy Carrier

“…The problem, though, is such cell configuration had to work at low temperatures where the kinetics of reaction were sluggish [102]. Moreover, an electrochemical cell is more advantageous when operating at higher temperatures since higher rates of reaction can be achieved in the same electrode area, and hydrazine development can be prevented [103]. As a result, proton (H + ) conductivity solid-state materials that operate at a temperature above 500 • C were developed [102].…”

Transition metal oxynitride catalysts for electrochemical reduction of nitrogen to ammonia

“…Ammonia (NH 3 ), a key precursor used to produce nitrogen-containing fertilizers, is currently produced by an energy intensive Haber-Bosch process [1][2][3][4][5][6][7][8] . The Haber-Bosch process is typically carried out at high temperatures (400-500 °C) and pressures (200-300 atm) where nitrogen from the atmosphere reacts with hydrogen produced from non-renewable resources to produce NH 3 [9][10][11] and consumes ~1-2% of global energy [12][13][14][15][16][17] .…”