Li Wenyi, Li Ke, Ye Yixing, Zhang Shengbo, Liu Yanyan, Wang Guozhong, Liang Changhao, Zhang Haimin, Zhao Huijun
Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, CAS Center for Excellence in Nanoscience, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China.
University of Science and Technology of China, Hefei, 230026, China.
Commun Chem. 2021 Jan 29;4(1):10. doi: 10.1038/s42004-021-00449-7.
The electrocatalytic nitrogen (N) reduction reaction (NRR) relies on the development of highly efficient electrocatalysts and electrocatalysis systems. Herein, we report a non-loading electrocatalysis system, where the electrocatalysts are dispersed in aqueous solution rather than loading them on electrode substrates. The system consists of aqueous Ag nanodots (AgNDs) as the catalyst and metallic titanium (Ti) mesh as the current collector for electrocatalytic NRR. The as-synthesized AgNDs, homogeneously dispersed in 0.1 M NaSO solution (pH = 10.5), can achieve an NH yield rate of 600.4 ± 23.0 μg h mg with a faradaic efficiency (FE) of 10.1 ± 0.7% at -0.25 V (vs. RHE). The FE can be further improved to be 20.1 ± 0.9% at the same potential by using Ti mesh modified with oxygen vacancy-rich TiO nanosheets as the current collector. Utilizing the aqueous AgNDs catalyst, a Ti plate based two-electrode configured flow-type electrochemical reactor was developed to achieve an NH yield rate of 804.5 ± 30.6 μg h mg with a FE of 8.2 ± 0.5% at a voltage of -1.8 V. The designed non-loading electrocatalysis system takes full advantage of the AgNDs' active sites for N adsorption and activation, following an alternative hydrogenation mechanism revealed by theoretical calculations.
电催化氮还原反应（NRR）依赖于高效电催化剂和电催化体系的发展。在此，我们报道了一种非负载型电催化体系，其中电催化剂分散在水溶液中，而非负载在电极基底上。该体系由作为催化剂的水相银纳米点（AgNDs）和作为电催化NRR集电器的金属钛（Ti）网组成。合成的AgNDs均匀分散在0.1 M NaSO溶液（pH = 10.5）中，在-0.25 V（相对于可逆氢电极，RHE）时，NH产率可达600.4±23.0 μg h mg，法拉第效率（FE）为10.1±0.7%。通过使用富含氧空位的TiO纳米片修饰的Ti网作为集电器，在相同电位下FE可进一步提高到20.1±0.9%。利用水相AgNDs催化剂，开发了一种基于Ti板的两电极配置流动型电化学反应器，在-1.8 V电压下，NH产率为804.5±30.6 μg h mg，FE为8.2±0.5%。所设计的非负载型电催化体系充分利用了AgNDs的活性位点进行氮吸附和活化，遵循理论计算揭示的交替加氢机制。
