A self-supported copper/copper oxide heterostructure derived from a copper-MOF for improved electrochemical nitrate reduction. Issue 21 (29th September 2022)

• Record Type: Journal Article
• Authors: Sun, Mengmiao; Wu, Guanzheng; Dai, Lei; Oschatz, Martin; Qin, Qing
• Is Part Of: Catalysis science & technology. Volume 12:Issue 21(2022)
• Page Start: 6572
• Page End: 6580
• Publication Date: 2022-09-29
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d2cy01427k
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Development of highly efficient NITRR electrocatalysts by using a copper/copper oxide heterostructure derived from a copper-MOF catalyst. A NITRR with remarkable faradaic efficiency and ammonia yield under ambient conditions is described. Abstract : The conversion of low-cost and abundant precursor substances into value-added chemicals through electrochemical techniques is a key element to build a renewable energy-chemistry cycle. Among the various available possibilities, the electrochemical nitrate reduction reaction (NITRR) has attracted more and more interest, as it can provide a novel route for ammonia (NH3 ) synthesis driven by electricity from renewable sources. However, the faradaic efficiency (FE) and production rate of NH3 are still limited by the multiple involved electron–proton-transfer steps and strong competition from the hydrogen evolution reaction. The rational design of efficient catalysts can contribute to overcoming these challenges. Herein, we report the synthesis of free-standing Cu-MOF-based materials as NITRR catalysts. Under electrochemical reduction conditions, the Cu-MOF electrode encounters both chemical reconstruction and structural change. The Cu species are partially reduced and form a unique Cu/Cu2 O/CuO heterostructure, resulting in remarkable NITRR performance. At a potential of −0.3 V vs. RHE, the FE of NH3 is as high as 99.5% with a production rate of 5.9 mg h −1 cm −1 . A satisfactory half-cell energy efficiency of 35.1% is achieved as well. Desirable stability is confirmed by a cycling test. Such an electrolyzer can be driven by a solar cell under the irradiation of natural sunlight for continuous NH3 production.