Synthesis of ammonia directly from wet air using new perovskite oxide La0.8Cs0.2Fe0.8Ni0.2O3-δ as catalyst

Single phase perovskite oxide La0.8Cs0.2Fe0.8Ni0.2O3-delta was synthesised to be used as electrocatalyst for electrochemical synthesis of ammonia directly from wet air. It exhibits an orthorhombic structure with space group Pnma(62); a=5.5493(5)angstrom, b=7.8352(10)angstrom, c=5. 5295(5) angstrom, V=240.42(4) angstrom(3). Composite made of Ce0.8Gd0 2O2-delta (CGO) and (Li,Na,K)(2)CO3 was used as electrolyte. An ammonia formation rate of 9.21 x 10(-7) mol s(-1) m(-2) was obtained at 400 degrees C when applied a voltage of 1.4 V, while wet air (3 mol% H2O was introduced to the single chamber reactor. This is just slightly lower than the value of 1.23 x 10(-6) mol s(-1) m(-2) when wet N-2 (3 mol% H2O) was fed under the same experimental conditions. These values are more than two orders of magnitude higher than the reported ammonia formation rates when synthesised from N-2 and H2O at similar to 600 degrees C. The perovskite catalyst is also low cost compared to the Ku/Mg and Pt/C catalysts in previous reports. This experiment indicates that ammonia can be directly synthesised from wet air using low-cost catalysts. This is a very promising simple technology for sustainable synthesis of ammonia in the future. (C) 2014 Elsevier Ltd. All rights reserved.