Precise Vacancy Fitting of Horizontal Dinitrogen for Ammonia Synthesis

作者：Bo Dai, Zichuang Li, Wenqian Li, Jiang Li, Xiaojun Lu, Kailong Qian, Ruoqian Jiang, Ying Zou, Yangfan Lu, Qing Zhang, Yanpeng Qi, Miao Xu, Feng Ryan Wang, Hideo Hosono, Jie‐Sheng Chen, Tian‐Nan Ye · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c08337 · 被引用次数：4 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、Advanced Photocatalysis Techniques、Phosphorus and nutrient management

Efficient ammonia synthesis under mild conditions remains a significant challenge in modern chemistry. Chemical looping ammonia synthesis (CLAS) presents a sustainable alternative for ammonia production under near-ambient pressure conditions. In this study, we introduce a “horizontal N 2 ” approach in the CLAS process, where an N 2 molecule is horizontally incorporated into the surface lattice of the catalyst, facilitating effective N 2 activation and subsequent NH 3 production. Utilizing barium carbide (BaC 2 ) as a model material, we show that the surface dianion vacancy sites of BaC 2 provide optimal spacing for N 2 activation, while the loaded Ni nanoparticles are responsible for H 2 activation, enabling N 2 hydrogenation from both ends to produce NH 3 under mild conditions. Resonant inelastic X-ray scattering (RIXS) analysis combined with computational calculations reveals that the rate-determining step of the CLAS process is the hydrogenation of *HNNH, significantly lowering the activation energy required for N 2 dissociation. The NH 3 production rate for Ni/BaC 2 is one order of magnitude higher than that reported for conventional CLAS catalysts and even surpasses the performance of the state-of-the-art 3d transition metal catalyst for catalytic ammonia synthesis at mild conditions of 100 °C and atmosphere. Unlike traditional CLAS catalysts, which typically suffer from deactivation, the dianion vacancy sites in Ni/BaC 2 demonstrate exceptional catalytic stability, main...