Electrochemical synthesis of ammonia from wet nitrogen using La_0.6Sr_0.4FeO_3−δ–Ce_0.8Gd_0.18Ca_0.02O_2−δcomposite cathode

Abstract

Ammonia was successfully synthesised directly from wet N2 at ∼400 °C based on an O2− ion conducting electrolyte.

Progress in the Electrochemical Synthesis of Ammonia

“…3). Using (Li,Na,K) 2 CO 3 -CGdC (30:70 wt%) as the electrolyte they studied three different cathodes: CoFe 2 O 4 [49], LSF [51] and LSCrF [52]. The most efficient of them was the LSCrF electrode mixed, with CGdC at a 70:30% wt ratio.…”

“…H2O -N2/Air 7.00 × 10 −11 (12.5) 0.22 [51] 375-425(375) include, changing the electrolyte (e.g. with bromides in place of chlorides, or organic salts) or the electrodes and the use of multiple cathodes.…”

Ammonia synthesis at atmospheric pressure in a BaCe0.2Zr0.7Y0.1O2.9 solid electrolyte cell

“…Thus, hydrogen sources that could eliminate natural gas could reduce the overall cost of ammonia production [1,2]. To this end, the electrochemical synthesis of ammonia from H 2 O, rather than H 2 , has been reported by various research groups in either liquid or solid electrolyte cells [13][14][15][16][17][18][19][20][21][22][23].…”

Synthesis of ammonia directly from wet nitrogen using a redox stable La0.75Sr0.25Cr0.5Fe0.5O3−δ–Ce0.8Gd0.18Ca0.02O2−δcomposite cathode

“…Fig. 33,34 The maximum ammonia formation rate was 4.0 Â 10 À10 mol s À1 cm À2 at 1.4 V. An ammonia formation rate of 7.0 Â 10 À11 mol s À1 cm À2 was observed for Cr-free Sr-doped LaFeO 3Àd , La 0.6 Sr 0.4 FeO 3Àd at 1.4 V and 400 C. 28 The ammonia formation rate is also higher than the 5 Â 10 À11 and 1.23 Â 10 À10 mol s À1 cm À2 at 1.4 V and 400 C when La 0.6 Sr 0.4 Fe 0.8 Cu 0.2 O 3Àd and La 0.8 Cs 0.2 Fe 0.8 Ni 0.2 O 3Àd was used as the cathode catalyst respectively for electrochemical synthesis of ammonia indicating LSCrF is potentially a better catalyst. Two depressed semicircles were observed.…”

“…Fe-containing perovskite oxides SmFe 0.7 Cu 0.1 Ni 0.2 O 3Àd (SFCN), SmBaCuFeO 5+d (SBCF) have been reported as cathode for electrochemical synthesis of ammonia from N 2 and H 2 based on electrochemical cells using Naon as the electrolyte. 28 To the best of our knowledge, there is no report on the electrochemical synthesis of ammonia using LSCrF as the catalyst. 23 We also investigated the use of perovskite oxide La 0.6 Sr 0.4 Fe 0.8 Cu 0.2 O 3Àd as the cathode and an ammonia formation rate of 5.39 Â 10 À9 mol s À1 cm À2 at 450 C was observed.…”