Pulse-Driven Active-Site Switching on Bromine-Modified Cu Enables Sequential 2e– + 6e– Nitrate-to-Ammonia Conversion
Pulse-Driven Active-Site Switching on Bromine-Modified Cu Enables Sequential 2e– + 6e– Nitrate-to-Ammonia Conversion
研究概述
结合微量Br修饰Cu/Cu2O与脉冲电位，动态调节Cu价态：较高价态促进硝酸盐还原为亚硝酸盐，较低价态促进后续六电子产氨步骤。氨法拉第效率94%，流动装置运行约700小时，并验证养殖尾水中氮向氨的回收。
谱图与表征信息
Figure 1. Structural characterizations of Br−Cu and Cu/Cu2O. (a) Schematic diagram for the preparation of the Br−Cu electrode. (b) SEM image of CuBr/Cu2O/Cu (left) and Br−Cu (right). The (c) Cu 2p and (d) Br 3d XPS spectra of Br−Cu and Cu/Cu2O. (e) Cu LMM Auger spectra of Br−Cu and Cu/Cu2O. (f) XANES spectra of Cu K-edge. (g) EXAFS spectra of Br−Cu, Cu/Cu2O, Cu-foil, Cu2O, and CuO. (h) Two-dimensional wavelet transform EXAFS plots for χ(k) EXAFS data collected for Br−Cu and Cu/Cu2O.
Figure 3. In situ revealed dynamic electronic modulation of Br−Cu under PE conditions. In situ Raman spectra of (a) Br−Cu, (b) Cu/Cu2O at PE and (c) Br−Cu at CE (−0.4 V/−0.8 V) conditions. (d) In situ Cu K-edge XANES spectra collected on Br−Cu under various potentials, (e) corresponding k2-weighted FT-EXAFS curves of Cu-foil, Cu2O, CuO, Cu/Cu2O, and Cu−Br. Two-dimensional (2D) wavelet transform EXAFS plots for χ(k) EXAFS data collected for (f) Br−Cu and (g) Cu/Cu2O under various potentials. (h) DOS of Br−Cu and Cu/Cu2O. (i) Differences of electron density and Bader charge for Br−Cu and Cu/Cu2O (isosurface = 0.003 a.u.).