Zhang Zhihao, Niu Aihui, Lv Yaxin, Guo Haoran, Chen Jun Song, Liu Qian, Dong Kai, Sun Xuping, Li Tingshuai
School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, 611731, Sichuan, China.
Department of Chemistry, Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan, 411105, Hunan, China.
Angew Chem Int Ed Engl. 2024 Jul 22;63(30):e202406441. doi: 10.1002/anie.202406441. Epub 2024 Jun 19.
Transition-metal carbides with metallic properties have been extensively used as electrocatalysts due to their excellent conductivity and unique electronic structures. Herein, NbC nanoparticles decorated carbon nanofibers (NbC@CNFs) are proposed as an efficient and robust catalyst for electrochemical synthesis of ammonia from nitrate/nitrite reduction, which achieves a high Faradaic efficiency (FE) of 94.4 % and a large ammonia yield of 30.9 mg h mg . In situ electrochemical tests reveal the nitrite reduction at the catalyst surface follows the *NO pathway and theoretical calculations reveal the formation of NbC@CNFs heterostructure significantly broadens density of states nearby the Fermi energy. Finite element simulations unveil that the current and electric field converge on the NbC nanoparticles along the fiber, suggesting the dispersed carbides are highly active for nitrite reduction.
具有金属特性的过渡金属碳化物因其优异的导电性和独特的电子结构而被广泛用作电催化剂。在此，提出了一种由碳化铌纳米颗粒修饰的碳纳米纤维（NbC@CNFs），作为一种高效且稳定的催化剂，用于通过硝酸盐/亚硝酸盐还原进行电化学合成氨，其法拉第效率（FE）高达94.4%，氨产率高达30.9 mg h mg。原位电化学测试表明，催化剂表面的亚硝酸盐还原遵循*NO途径，理论计算表明，NbC@CNFs异质结构的形成显著拓宽了费米能级附近的态密度。有限元模拟表明，电流和电场沿纤维在NbC纳米颗粒上汇聚，这表明分散的碳化物对亚硝酸盐还原具有高活性。
