高効率マンガン系アンモニア合成触媒を開発（Scientists Develop Efficient Mn-based Catalyst for Ammonia Synthesis）

2026-05-29 中国科学院（CAS）

＜関連情報＞

• https://english.cas.cn/newsroom/research-news/202605/t20260530_1160192.shtml
• https://onlinelibrary.wiley.com/doi/10.1002/anie.6169961

A原子レベルで分散したMnとLiBaH3がMgO上で相乗効果を発揮し、 H−アシストN2解離機構を介して効率的なアンモニア合成を可能にする tomically Dispersed Mn Synergized With LiBaH3 on MgO Enables Efficient Ammonia Synthesis via an H− Assisted N2 Dissociation Mechanism

Yanbo Deng, Yaoqi Huang, Yongcheng Jin, Yawei Wang, Runze Wang, Sheng Feng, Yongli Cai, Yeqin Guan, Qianru Wang, Xilun Zhang, Fei Chang, Shaojun Yuan, Wenbo Gao, Jianping Guo, Ping Chen
Angewandte Chemie International Edition  Published: 15 May 2026
DOI:https://doi.org/10.1002/anie.6169961

Graphical Abstract

Atomically dispersed Mn (Mn₁) anchored on LiBaH₃ enables efficient ammonia synthesis via an H⁻-assisted N₂ dissociation pathway. Mn₁ provides the active site for N₂ adsorption, while hydride ions from LiBaH₃ promote reductive protonation to form *N₂H. This synergistic mechanism yields state-of-the-art performance among group 4–7 transition-metal catalysts.

ABSTRACT

Ammonia is an essential chemical feedstock and a promising hydrogen energy carrier, motivating the development of efficient ammonia synthesis catalysts. However, scaling relations fundamentally limit conventional transition metal-based catalysts, rendering strongly N₂-binding metals such as Mn ineffective due to sluggish hydrogenation. Herein, we demonstrate that atomically dispersed Mn (Mn₁) anchored on the ternary hydride LiBaH₃ (LiBaH₃─Mn₁) enables efficient ammonia synthesis via an H⁻ ion-assisted N₂ dissociation mechanism. The MgO supported LiBaH₃─Mn₁ catalyst (LiBaH₃─Mn₁/MgO) exhibits an ammonia synthesis rate two orders of magnitude higher than that of manganese nitride and exceeds the benchmark Cs─Ru/MgO catalyst by a factor of 2.5 at 400°C, representing a state-of-the-art performance among group 4–7 transition metal–based catalysts. Mechanistic investigations reveal that Mn₁ serves as the active site for N₂ adsorption, while H⁻ ions from LiBaH₃ further activate the adsorbed *N₂ through a reductive protonation process to form *N₂H intermediates. Subsequent N─N bond cleavage of *N₂H yields surface nitride (Mn─N) and imide (*NH) species on the LiBaH₃─Mn₁ surface. This H⁻ ion-assisted N₂ dissociation pathway fundamentally overcomes the intrinsic limitations of bulk Mn, transforming it into an efficient metal for ammonia synthesis.