Giri Pratibha Kiran, Rawat Anuj, Sk Mukaddar, Swain Bishnupriya, Thapa Ranjit, Mohanty Paritosh
Functional Materials Laboratory, Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, 247667, India.
Department of Physics, SRM University AP, Amaravati, Andhra Pradesh, 522240, India.
Small Methods. 2025 May 2:e2500655. doi: 10.1002/smtd.202500655.
A significant research gap in the field of synthesis of single atom catalysts (SACs) is addressed by developing a low-temperature complexation approach to stabilize the single metal atoms on stacked polytiazine matrix (g-CN) with a good metal loading. Unlike conventional high-energy (400-700 °C) and time-intensive (120-300 min) methods typically used for embedding SACs in g-CN matrices, the present synthesis utilizes a facile, microwave-assisted method that operates at a low temperature of 140 °C and completes within 30 min. Comprehensive analysis reveal that complexation of the Cu/Cu ions with nitrogen in the polytriazine structure facilitates layer stacking. Specifically, Cu⁺ ions promote sheet formation in co-ordination with two nearby N atoms, while Cu ions stabilize the stacked layers of the polytriazine framework through co-ordination with four N atoms. The resulting SAC exhibits a Cu metal loading up to 3.5 wt.%, with a specific surface area (SA) of 330 m g and pore size distribution centered at 1.9 and 5 nm. The SAC demonstrates excellent catalytic performance for click cycloaddition reactions under base-free conditions, with a high turnover frequency (TOF) of 120 h, a broad substrate scope, and reusability across seven cycles without detectable Cu leaching, making it a promising SAC for triazole synthesis.
通过开发一种低温络合方法，在具有良好金属负载量的堆叠聚噻嗪基质（g-CN）上稳定单金属原子，解决了单原子催化剂（SACs）合成领域中一个重大的研究空白。与通常用于将SACs嵌入g-CN基质的传统高能（400-700°C）和耗时（120-300分钟）方法不同，本合成方法采用了一种简便的微波辅助方法，该方法在140°C的低温下运行，并在30分钟内完成。综合分析表明，Cu/Cu离子与聚三嗪结构中的氮络合促进了层堆叠。具体而言，Cu⁺离子与两个相邻的N原子配位促进片层形成，而Cu离子通过与四个N原子配位稳定聚三嗪骨架的堆叠层。所得的SAC显示出高达3.5 wt.%的Cu金属负载量，比表面积（SA）为330 m²/g，孔径分布集中在1.9和5 nm。该SAC在无碱条件下对点击环加成反应表现出优异的催化性能，具有120 h的高周转频率（TOF）、广泛的底物范围，并且在七个循环中可重复使用且无明显的Cu浸出，使其成为一种有前途的用于三唑合成的SAC。
