Lan Xingwang, Li Yiming, Du Cheng, She Tiantian, Li Qing, Bai Guoyi
Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding, Hebei, 071002, P. R. China.
Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Weijin Road 92, Tianjin, 300072, P. R. China.
Chemistry. 2019 Jun 26;25(36):8560-8569. doi: 10.1002/chem.201900563. Epub 2019 May 30.
Porous carbon nitride frameworks (PCNFs) with uniform and rich nitrogen dopants and abundant porosity were successfully fabricated through the direct carbonization of the covalent triazine frameworks (CTFs) at different pyrolysis temperatures and used as supports to anchor and stabilize Ag nanoparticles (NPs) for catalytic CO conversion. Importantly, the pyrolysis temperature plays a crucial role in the properties of porous carbon nitride frameworks. The material carbonized at 700 °C showed the highest surface area and micro- and mesoporous structure with a certain interlayer distance. Taking advantage of their unique surface characteristics, PCNF-supported Ag NP catalysts (Ag/PCNF-T, T=pyrolysis temperature) were prepared by a simple chemical method. A series of characterizations revealed that Ag NPs are embedded in the porous carbon nitride frameworks and confined to a relatively small size with high dispersion owing to the assistance of the abundant surface groups and porous structures. The as-obtained Ag/PCNF-T catalysts, especially Ag/PCNF-700, showed excellent catalytic activity, selectivity, and stability for the carboxylation of CO with terminal alkynes under mild conditions. This can be due to the existence of abundant nitrogen atoms and diverse porosity, which resulted in highly efficient catalytic activity and stability.
通过在不同热解温度下对共价三嗪骨架（CTFs）进行直接碳化，成功制备了具有均匀且丰富的氮掺杂剂以及丰富孔隙率的多孔氮化碳骨架（PCNFs），并将其用作载体来锚定和稳定银纳米颗粒（NPs）以用于催化CO转化。重要的是，热解温度对多孔氮化碳骨架的性能起着至关重要的作用。在700°C碳化的材料表现出最高的表面积以及具有一定层间距的微孔和介孔结构。利用其独特的表面特性，通过简单的化学方法制备了PCNF负载的Ag NP催化剂（Ag/PCNF-T，T =热解温度）。一系列表征表明，由于丰富的表面基团和多孔结构的辅助，Ag NPs嵌入多孔氮化碳骨架中并被限制在相对较小的尺寸且具有高分散性。所制备的Ag/PCNF-T催化剂，尤其是Ag/PCNF-700，在温和条件下对CO与末端炔烃的羧基化反应表现出优异的催化活性、选择性和稳定性。这可能是由于存在丰富的氮原子和多样的孔隙率，从而导致了高效的催化活性和稳定性。
