日本东京科学研究所Masaaki Kitano研究小组揭示了负离子空位激活Ba-Si正硅酸氧氮氢化物上的N2到氨。这一研究成果发表在2025年2月17日出版的国际学术期刊《自然-化学》上。

在这里，该课题组研究人员报道了一种Ba-Si正硅酸氮氧氢化物作为无过渡金属催化剂，通过阴离子空位介导的机制高效合成氨。H^-的快速解吸和N^3-阴离子利用晶体结构的灵活性可以在空位位置容纳高密度的电子，在空位位置N₂可以被捕获并通过氢化过程直接活化成氨。通过负载钌纳米粒子，氨合成速率达到40.1 mmol g^-1 h^-1。虽然没有发现Ru能解离N₂，但它反而促进了Ru -载体界面上阴离子空位的形成。这为阴离子空位介导的多相异构催化开辟了一条新的途径。

据悉，金属氧化物表面的阴离子空位在各种氧化/还原化学反应中作为活性位或促进位进行了研究。然而，在没有过渡金属的情况下，氧化物材料很少能有效地作为催化剂。

附：英文原文

Title: Anion vacancies activate N2 to ammonia on Ba–Si orthosilicate oxynitride-hydride

Author: Zhang, Zhujun, Miyashita, Kazuki, Wu, Tong, Kujirai, Jun, Ogasawara, Kiya, Li, Jiang, Jiang, Yihao, Miyazaki, Masayoshi, Matsuishi, Satoru, Sasase, Masato, Tada, Tomofumi, Hosono, Hideo, Kitano, Masaaki

Issue&Volume: 2025-02-17

Abstract: Anion vacancies on metal oxide surfaces have been studied as either active sites or promoting sites in various chemical reactions involving oxidation/reduction processes. However, oxide materials rarely work effectively as catalysts in the absence of transition metal sites. Here we report a Ba–Si orthosilicate oxynitride–hydride as a transition-metal-free catalyst for efficient ammonia synthesis via an anion-vacancy-mediated mechanism. The facile desorption of H^- and N^3- anions plus the flexibility of the crystal structure can accommodate a high density of electrons at vacancy sites, where N₂ can be captured and directly activated to ammonia through hydrogenation processes. The ammonia synthesis rates reach 40.1mmolg^-1 h^-1 at 300°C by loading ruthenium nanoparticles. Although not found to dissociate N₂, Ru instead facilitates the formation of anion vacancies at the Ru–support interface. This demonstrates a new route for anion-vacancy-mediated heterogeneous catalysis.

DOI: 10.1038/s41557-025-01737-8

Source: https://www.nature.com/articles/s41557-025-01737-8