Construction of Oxygen Vacancy-Rich TiO2 Nanocrystals for Boosting the Ammonolysis of Caprolactam to 6-Aminocapronitrile

• DOI: 10.1021/acsami.3c19591
• Publication Date: 2024-03-11T19:42:03Z
• Authors: Qihui Huang; Hui Zheng; Xia Wang; Qi Fu; Tao Gong; Chang Liu; Huijuan Ma; Linmin Ye; Xinping Duan; Youzhu Yuan
• Keywords: Caprolactam; Boosting

Hexamethylene diamine, an important chemical intermediate for polyamides, can be synthesized through the two-step route of caprolactam (CPL) ammonolysis to 6-aminocapronitrile (ACN), followed by hydrogenation. This method has received increasing attention from academia and industry. However, studies on catalyst structure-performance correlation in CPL are still sporadic. In this work, a series anatase TiO2 with different oxygen vacancy concentrations was prepared reduction using NaBH4. The surface, presented as Ti3+ sites, substantially enhances adsorption activation NH3, which demonstrated key steps ammonolysis. Owing synergistic effect Ti4+ species, conversion rate ACN selectivity 85 97%, respectively, achieved within 250 h. Density functional theory calculations showed that intermediates vacancy-rich had more favorable energy compared those intact TiO2, is good agreement experimental results.