Splicing the active phases of copper/cobalt-based catalysts achieves high-rate tandem electroreduction of nitrate to ammonia.
Splicing the active phases of copper/cobalt-based catalysts achieves high-rate tandem electroreduction of nitrate to ammonia.
复制标题
将铜/钴基催化剂的活性相接接，实现了硝酸盐的高速率串联电还原制氨。
DOI：
10.1038/s41467-022-28728-4
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发表时间：
2022-03-02
影响因子：
16.6
通讯作者：
Schuhmann W
中科院分区：
文献类型：
--
作者：
He W;Zhang J;Dieckhöfer S;Varhade S;Brix AC;Lielpetere A;Seisel S;Junqueira JRC;Schuhmann W
在环境条件下，电催化废硝酸盐（NO3−）回收为有价氨（NH3）是一种绿色且有吸引力的替代Haber - Bosch工艺。然而，该反应需要多步电子和质子转移，这使得以节能的方式驱动高速率NH3合成成为一个巨大的挑战。在此，我们提出了串联催化剂的设计概念，其中包括耦合存在于低应用过电位的不同过渡金属的中间相，作为合作活性位点，实现级联NO3−到nh3的转化，从而避免了通常遇到的结垢关系。我们通过电化学将Cu - Co二元硫化物转化为电位依赖的核壳Cu/CuOx和Co/CoO相来实现这一概念。电化学评价、动力学研究和原位拉曼光谱表明，Cu/CuOx内相优先催化NO3−还原为NO2−，而NO2−在附近的Co/CoO层迅速还原为NH3。这种独特的串联催化剂体系在pH为13的大范围NO3−浓度下，NO3−转化为NH3的法拉第效率为93.3±2.1%，在0.1 M NO3−条件下，NH3产率高达1.17 mmol cm−2 h−1，与RHE相比，NH3产率为- 0.175 V，半电池能量效率为~36%，超过了大多数先前的报道。在环境条件下电催化回收废硝酸盐生成NH3可能是Haber - Bosch法的一个有吸引力的替代方法。本文报道了一种串联催化剂体系，该体系在不同的过渡金属活性位点上协同吸附反应中间体，用于硝酸盐电还原。
Electrocatalytic recycling of waste nitrate (NO3−) to valuable ammonia (NH3) at ambient conditions is a green and appealing alternative to the Haber−Bosch process. However, the reaction requires multi-step electron and proton transfer, making it a grand challenge to drive high-rate NH3 synthesis in an energy-efficient way. Herein, we present a design concept of tandem catalysts, which involves coupling intermediate phases of different transition metals, existing at low applied overpotentials, as cooperative active sites that enable cascade NO3−-to-NH3 conversion, in turn avoiding the generally encountered scaling relations. We implement the concept by electrochemical transformation of Cu−Co binary sulfides into potential-dependent core−shell Cu/CuOx and Co/CoO phases. Electrochemical evaluation, kinetic studies, and in−situ Raman spectra reveal that the inner Cu/CuOx phases preferentially catalyze NO3− reduction to NO2−, which is rapidly reduced to NH3 at the nearby Co/CoO shell. This unique tandem catalyst system leads to a NO3−-to-NH3 Faradaic efficiency of 93.3 ± 2.1% in a wide range of NO3− concentrations at pH 13, a high NH3 yield rate of 1.17 mmol cm−2 h−1 in 0.1 M NO3− at −0.175 V vs. RHE, and a half-cell energy efficiency of ~36%, surpassing most previous reports. Electrocatalytic recycling of waste nitrate to NH3 under ambient conditions maybe an appealing alternative to the Haber−Bosch process. Here the authors report a tandem catalyst system involving cooperative adsorption of reaction intermediate on different transition metal active sites for nitrate electroreduction with high efficiency.
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影响因子：
22
作者：
Hodgetts, Rebecca Y.;Kiryutin, Alexey S.;Simonov, Alexandr N.
通讯作者：
Simonov, Alexandr N.
DOI：
10.1002/chem.202100387
发表时间：
2021-04-01
期刊：
Chemistry (Weinheim an der Bergstrasse, Germany)
影响因子：
--
作者：
Dieckhöfer S;Öhl D;Junqueira JRC;Quast T;Turek T;Schuhmann W
通讯作者：
Schuhmann W
影响因子：
4.5
作者：
Dima, GE;de Vooys, ACA;Koper, MTM
通讯作者：
Koper, MTM
影响因子：
15
作者：
Chen, Gao-Feng;Cao, Xinrui;Wang, Haihui
通讯作者：
Wang, Haihui
影响因子：
29.4
作者：
Geng, Zhigang;Liu, Yan;Zeng, Jie
通讯作者：
Zeng, Jie