Solid-state electrochemical synthesis of ammonia: a review

Ibrahim A. Amar, Rong Lan, Christophe T. G. Petit, Shanwen Tao

Research output: Contribution to journalLiterature review

162 Citations (Scopus)

Abstract

Ammonia is one of the most produced chemicals worldwide, and it is not only a major end product but also an important energy storage intermediate. The solid-state electrochemical synthesis of ammonia has the promise to overcome the limitations of the conventional catalytic reactors such as the limited conversion, severe environmental pollution and high energy consumption. Solid-state electrolytes either protonic or oxide ion conductors have been reviewed and particular emphasis is placed on their application to synthesise ammonia. The highest rate of ammonia formation according to the type of electrolyte utilised were in the following order; solid polymers > Ce0.8Gd0.2O2-delta-(Ca-3(PO4)(2)-K3PO4) composites > fluorites > perovskites > pyrochlores although the catalysts in electrodes also play an important role. The highest rate reported so far is found to be 1.13 x 10(-8) mol s(-1) cm(-2) at 80 A degrees C with a potential of 2 V using Nafion membrane, SmFe0.7Cu0.1Ni0.2O3 (SFCN), and Ni-Ce0.8Sm0.2O2-delta as solid electrolyte, cathode and anode, respectively. Synthesising ammonia from steam and N-2, by-passing H-2 stage offers many advantages such as reduction of device numbers and then the overall costs. The factors affecting the rate of ammonia formation have been discussed as well.

Original languageEnglish
Pages (from-to)1845-1860
Number of pages16
JournalJournal of Solid State Electrochemistry
Volume15
Issue number9
Early online date6 Apr 2011
DOIs
Publication statusPublished - Sep 2011

    Fingerprint

Keywords

  • electrochemical synthesis of ammonia
  • solid-state electrolyte
  • proton conductor
  • oxide-ion conductor
  • oxide fuel-cells
  • proton conductor BA3CA1.18NB1.82O9-delta
  • perovskite-type oxides
  • atmospheric-pressure
  • high-temperature
  • intermediate-temperature
  • doped baceo3
  • composite electrolyte
  • heterogeneous catalysis
  • hydrogen permeability

Cite this