无金属磷掺杂氮化碳催化N-杂环化合物无氧脱氢

Metal-free P-doped carbon nitride catalyst for acceptorless dehydrogenation of N-heterocycles

以纳米二氧化硅为模板剂、乙二胺和四氯化碳为前驱体、四苯基氯化磷为磷源,经聚合-碳化法合成介孔磷掺杂氮化碳催化剂(CN-xP).在N-杂环化合物脱氢生成芳香N-杂环的反应中,CN-xP的催化活性明显高于无磷掺杂的氮化碳催化剂,且调节磷源添加量可进一步提升其催化活性.研究发现:以CN-6P为最优催化剂,在150℃下反应2 h, N-杂环化合物的转化率可达100%,选择性在99%以上.催化剂具有良好的底物普适性和较好的循环稳定性.

P-doped carbon nitride catalysts(CN-xP) were synthesized through polymerization-carbonization strategy by using nano-SiOas template, ethylenediamine and carbon tetrachloride as precursors, tetraphenylphosphorus chloride as phosphorus source. In the dehydrogenation of N-heterocycles to aromatic N-heterocycles, the catalytic activity of CN-xP was significantly higher than that of phosphorus-free carbon nitride catalyst, and the catalytic activity could be further improved by adjusting the amount of phosphorus source. The results show that, with CN-6 P as the optimal catalyst, N-heterocycles 100% conversion and over 99% quinoline selectivity can be achieved at 150 ℃ for 2 h. The catalyst has good substrate tolerance and nice stability.