Electrochemical Acceleration of Ammonia Synthesis on Fe-Based Alkali-Promoted Electrocatalyst with Proton Conducting Solid Electrolyte

Abstract

To accelerate ammonia synthesis, the effect of the electrode potential on the kinetics of ammonia synthesis was investigated with a proton-conducting solid electrolyte, BaCe 0.9 Y 0.1 O 3 (BCY), at temperatures between 500−650 °C. Ammonia synthesis was conducted using a double chamber electrochemical setup with an electrolyte-supported Pt|BCY| K,Al-modified Fe-BCY cell. Although slow ammonia formation kinetics by cathodic polarization was observed when pure N 2 was supplied to the cathode side, obvious acceleration of the ammonia formation rate by cathodic polarization was observed following addition of 15% H 2 to the cathode side. The ammonia formation rate increased more than 20 times at −1.5 V relative to that at the open circuit voltage, which was not observed by anodic polarization. Notably, the acceleration at the cathodic potential was observed over 610 °C. These results indicate that the enhancement of ammonia formation occurs because of promotion of nitrogen dissociation by cathodic polarization and a change in the transport properties of the BCY electrolyte. The acceleration mechanism was discussed based on kinetic measurements and the dependence of the reaction kinetics on temperature and partial pressure.

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Highly Effective Ru/BaCeO3 Catalysts on Supports with Strong Basic Sites for Ammonia Synthesis

“…Otomo et al used aB aCe 0.9 Y 0.1 O 3 proton-conducting solid electrolyte to investigate the effect of electrode potential on the kinetics of ammonia synthesis;t he resultss howed that the proton-conducting ability of the BaCe 0.9 Y 0.1 O 3 electrolyte promotes the dissociation of nitrogen. [12] It is known that the electron-donating ability of BaCeO 3 is related to its basic sites. [13] However,t here are few reports on the effecto fb asic sites of the BaCeO 3 support on ammonia synthesis performance.…”

Theory-guided materials design: two-dimensional MXenes in electro- and photocatalysis

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