Carbon black supported manganese phthalocyanine: Efficient electrocatalyst for nitrogen reduction to ammonia

Abstract

Abstract Ammonia (NH 3 ) is regarded as a renewable energy source as well as an important molecule for agricultural applications. The energy‐intensive Haber‐Bosch method produces large amounts of CO 2 gas during ammonia production. As an alternative, there has recently been much interest in the electrocatalytic production of NH 3 via the electrochemical nitrogen reduction reaction (ENRR) process utilizing renewable energy under ambient condition. Herein, we report a conducting carbon–supported manganese phthalocyanine electrocatalyst as an efficient electrocatalyst for ENRR applications. The MnPc electrocatalyst exhibited the activity with an ammonia production rate of 61.8 μg h −1 mg −1 cat with Faradaic efficiency (FE) of 31.3% @–0.4 V vs. RHE, respectively, under ambient condition in 0.1 M HCl solution whereas MnPc/C electrocatalyst exhibited an enhanced the productivity with an ammonia yield rate of 127.7 μg h −1 mg −1 cat with FE of 35.3% @–0.4 V vs. RHE, respectively. The reliability of N origin in ammonia formation is demonstrated by 1 H‐NMR experiments and multiple control analysis. These results open the way for the further study of carbon‐supported transition‐metal phthalocyanine compounds for electrochemical nitrogen fixation to NH 3 .