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

Abstract

The catalytic and electrocatalytic synthesis of ammonia from its elements was studied in a proton conducting single-chamber solid electrolyte cell. The BaCe0.2Zr0.7Y0.1O2.9 (BCZY27) proton conducting ceramic was used as the electrolyte. A Ni-BCZY27 cermet and a Rh film were the two electrodes. The reaction was studied at atmospheric pressure and at temperatures between 450°C and 650°C, under both, open- and closed-circuit conditions. The highest improvement (40%) in the open-circuit rate was attained at 550°C and for PH2/PN2=1.0. The corresponding purely electrocatalytic rate (difference between closed-circuit and open-circuit rate) was 2.9×10−9mol⋅s−1⋅cm−2. This value is among the highest reported for electrochemical ammonia synthesis.