Local Proton Source Enhanced Nitrogen Reduction on a Combined Cobalt‐Molybdenum Catalyst for Electrochemical Ammonia Synthesis
Sunki Chung, HyungKuk Ju, Minjun Choi, Donghyun Yoon, Jaeyoung Lee
Abstract
Abstract Electrochemical nitrogen reduction reaction (NRR) under ambient conditions has attracted considerable scientific and engineering interest as a green alternative route for NH 3 production. Molybdenum is a promising candidate as an electrocatalyst for NRR as it has a suitable binding strength with N species. However, the design of an efficient Mo‐based catalyst remains elusive. To enhance the selectivity of NRR toward NH 3 , we have developed a carbon nanofiber catalyst embedded with molybdenum and cobalt (Co−Mo−CNF). Co with a strong ability to dissociate water enhances local proton source near Mo, where the hydrogenation step of the NRR occurs. A NH 3 formation rate of 72.72 μg h −1 mg −1 and a Faradaic efficiency of 34.5 % were obtained at −0.5 V vs. RHE. We also attempted to provide a mechanistic understanding of the NRR via in situ attenuated total reflectance surface‐enhanced infrared absorption spectroscopy (ATR‐SEIRAS) and isotopic labeling experiments using 15 N 2 and D 2 O.