Zhang Rong, Ji Lei, Kong Wenhan, Wang Huanbo, Zhao Runbo, Chen Hongyu, Li Tingshuai, Li Baihai, Luo Yonglan, Sun Xuping
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, China.
School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China.
Chem Commun (Camb). 2019 May 8;55(36):5263-5266. doi: 10.1039/c9cc01703h. Epub 2019 Apr 17.
Electrocatalytic N reduction represents a promising alternative to the conventional Haber-Bosch process for ambient N-to-NH fixation, but it is severely challenged by competitive hydrogen evolution, which limits the current efficiency for NH formation. In this work, a nanosheet array of metallic Bi, an environmentally benign elemental substance previously predicted theoretically to have low hydrogen-evolving activity, is proposed as a superior catalyst for N reduction electrocatalysis. Electrochemical tests show that the Bi nanosheet array on Cu foil as a stable 3D catalyst electrode achieves a high faradaic efficiency of 10.26% with an NH yield rate of 6.89 × 10 mol s cm at -0.50 V vs. the reversible hydrogen electrode in 0.1 M HCl, rivalling the performances of most reported noble-metal-free catalysts operating in acids. Density functional theory calculations suggest that Bi effectively activates the N[triple bond, length as m-dash]N bond and the alternating mechanism is energetically favourable.
电催化氮还原是传统哈伯-博施法在环境条件下固氮的一种有前景的替代方法，但它受到竞争性析氢的严重挑战，这限制了氨生成的电流效率。在这项工作中，金属铋纳米片阵列被提出作为一种用于氮还原电催化的优异催化剂，铋是一种环境友好的元素物质，此前理论预测其具有较低的析氢活性。电化学测试表明，铜箔上的铋纳米片阵列作为稳定的三维催化剂电极，在0.1 M HCl中相对于可逆氢电极在-0.50 V时实现了10.26%的高法拉第效率，氨产率为6.89×10⁻¹⁰ mol s⁻¹ cm⁻²，可与大多数报道的在酸性条件下运行的无贵金属催化剂的性能相媲美。密度泛函理论计算表明，铋能有效活化N≡N键，且交替机制在能量上是有利的。
