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Unveiling the Activity Origin of a Copper‐based Electrocatalyst for Selective Nitrate Reduction to Ammonia
Author(s) -
Wang Yuting,
Zhou Wei,
Jia Ranran,
Yu Yifu,
Zhang Bin
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201915992
Subject(s) - electrocatalyst , ammonia , chemistry , inorganic chemistry , faraday efficiency , selectivity , catalysis , nitrate , electrochemistry , copper , ammonia production , raman spectroscopy , electrode , organic chemistry , physics , optics
Unveiling the active phase of catalytic materials under reaction conditions is important for the construction of efficient electrocatalysts for selective nitrate reduction to ammonia. The origin of the prominent activity enhancement for CuO (Faradaic efficiency: 95.8 %, Selectivity: 81.2 %) toward selective nitrate electroreduction to ammonia was probed. 15 N isotope labeling experiments showed that ammonia originated from nitrate reduction. 1 H NMR spectroscopy and colorimetric methods were performed to quantify ammonia. In situ Raman and ex situ experiments revealed that CuO was electrochemically converted into Cu/Cu 2 O, which serves as an active phase. The combined results of online differential electrochemical mass spectrometry (DEMS) and DFT calculations demonstrated that the electron transfer from Cu 2 O to Cu at the interface could facilitate the formation of *NOH intermediate and suppress the hydrogen evolution reaction, leading to high selectivity and Faradaic efficiency.