Symmetry-Breaking <i>p</i>-Block Antimony Single Atoms Trigger N-Bridged Titanium Sites for Electrocatalytic Nitrogen Reduction with High Efficiency
Hongfei Gu, Jiani Li, Xiangfu Niu, Jie Lin, Li‐Wei Chen, Zedong Zhang, Ziqian Shi, Zhiyi Sun, Qingqing Liu, Peng Zhang, Wensheng Yan, Yu Wang, Liang Zhang, Pengfei Li, Xinyuan Li, Dingsheng Wang, Penggang Yin, Wenxing Chen
Abstract
The electrochemical nitrogen reduction reaction (eNRR) under mild conditions emerges as a promising approach to produce ammonia (NH 3 ) compared to the typical Haber–Bosch process. Herein, we design an asymmetrically coordinated p -block antimony single-atom catalyst immobilized on nitrogen-doped Ti 3 C 2 T x (Sb SA/N-Ti 3 C 2 T x ) for eNRR, which exhibits ultrahigh NH 3 yield (108.3 μg h –1 mg cat –1 ) and excellent Faradaic efficiency (41.2%) at −0.3 V vs RHE. Complementary in situ spectroscopies with theoretical calculations reveal that the nitrogen-bridged two titanium atoms triggered by an adjacent asymmetrical Sb–N 1 C 2 moiety act as the active sites for facilitating the protonation of the rate-determining step from *N 2 to *N 2 H and the kinetic conversion of key intermediates during eNRR. Moreover, the introduction of Sb–N 1 C 2 promotes the formation of oxygen vacancies to expose more titanium sites. This work presents a strategy for single-atom-decorated ultrathin two-dimensional materials with the aim of simultaneously enhancing NH 3 yield and Faradaic efficiency for electrocatalytic nitrogen reduction.