Breaking Linear Scaling Relation Limitations on a Dual‐Driven Single‐Atom Copper‐Tungsten Oxide Catalyst for Ammonia Synthesis
Fei Shen, Shuxian He, Xiangyi Tang, Yinan Liu, Yuying Wang, Yanjun Yin, Xiaoshu Lv, Wenyang Fu, Yan Zou, Guangming Jiang, Li’an Hou
Abstract
Abstract Electrocatalytic reduction of nitrate (NO 3 − , NO3RR) on single‐atom copper catalysts (Cu‐SACs) offers a sustainable approach to ammonia (NH 3 ) synthesis using NO 3 − pollutants as feedstocks. Nevertheless, this process suffers from inferior NO3RR kinetics and nitrite accumulation owing to the linear scaling relation limitations for SACs. To break these limitations, a single‐atom Cu‐bearing tungsten oxide catalyst (Cu 1 /WO 3 ) was developed, which mediated a unique dual‐driven NO3RR process. Specifically, WO 3 dissociated water molecules and supplied the Cu 1 site with ample protons, whereas the Cu 1 site in an electron‐deficient state converted NO 3 − to NH 3 efficiently. The Cu 1 /WO 3 delivered an impressive NH 3 production rate of 1274.4 mg N h −1 g Cu −1 , a NH 3 selectivity of 99.2%, and a faradaic efficiency of 93.7% at −0.60 V, surpassing most reported catalysts. Furthermore, an integrated continuous‐flow system consisting of a NO3RR cell and a vacuum‐driven membrane separator was developed for NH 3 synthesis from nitrate‐contaminated water. Fed with the Yangtze River water containing ∼22.5 mg L −1 of NO 3 − ‐N, this system realized an NH 3 production rate of 325.9 mg N h −1 g Cu −1 and a collection efficiency of 98.3% at energy consumption of 17.11 kwh g N −1 . This study provides a new dual‐driven concept for catalyst design and establishes a foundation for sustainable NH 3 synthesis from waste.