Unveiling structural evolution of Fe single atom catalyst in nitrate reduction for enhanced electrocatalytic ammonia synthesis

被引：10

作者：

Cheng, Xusheng ^{[1
]}

Shang, Wenzhe ^{[1
]}

Li, Yuehui ^{[1
]}

Hu, Jinwen ^{[1
]}

Guo, Jingya ^{[1
]}

Cao, Dequan ^{[1
]}

Zhang, Naitian ^{[1
]}

Zhang, Songlin ^{[1
]}

Song, Suchan ^{[1
]}

Liu, Tianna ^{[1
]}

Liu, Wei ^{[1
]}

Shi, Yantao ^{[1
]}

机构：

[1] Dalian Univ Technol, Frontier Sci Ctr Smart Mat, Sch Chem, State Key Lab Fine Chem, Dalian 116024, Peoples R China

来源：

NANO RESEARCH | 2024年 / 17卷 / 08期

基金：

中国国家自然科学基金; 中国博士后科学基金;

关键词：

structural evolution; Fe single atom catalysis; in-situ X-ray absorption spectroscopy; nitrate reduction to ammonia; SITES;

D O I：

10.1007/s12274-024-6628-z

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Atomic transition metal-nitrogen-carbon electrocatalysts exhibit outstanding activity in various electrocatalytic reactions. The challenge lies in predicting the structure of the active center, which may undergo changes under applied potential and interact with reactants or intermediates. Advanced characterization techniques, particularly in-situ X-ray absorption spectroscopy (XAS), provide crucial insights into the structural evolution of the metal active center during the reaction. In this study, nitrate reduction to ammonia (NO3RR) was selected as a model reaction, and we introduced in-situ XAS to reveal the structural evolution during the catalytic process. A novel single atom catalyst of iron loaded on three-dimensional nitrogen-carbon nanonetwork (designated as Fe SAC/NC) was successfully synthesized. We unraveled the structural transformations occurring as pyrrole-N4-Fe transitions to pyrrole-N-3-Fe throughout the NO3RR process. Notably, the Fe SAC/NC catalyst exhibited excellent catalytic activity, achieving a Faradaic efficiency of 98.2% and an ammonia generation rate of 22,515 mu g<middle dot>h(-1)<middle dot>mg(cat)(-1) at -0.8 V versus reversible hydrogen electrode. Theoretical calculations combined with in-situ spectroscopic characterization showed that pyrrole-N3-Fe reduced the energy barrier from *NO to *NHO and improved the selectivity of ammonia. This provides a robust reference for the design of efficient nitrate-to-ammonia synthesis catalysts.

引用

页码：6826 / 6832

页数：7