MA Yangbo,YANG Jianming, WANG Bo, ZHANG Wei, LÜJian

(Xi’an Modern Chemistry Research Institute,Shaanxi Xi’an 710065, China)

Abstract: The catalytic performance of KNO₃/AC supported solid bases for the synthesis of CF₃I via pentafluoroethane with iodin was investigated. Scanning electron microscopy(SEM), N₂ physisorption, DSC/TG-MS coupling technology, Fourier-transform infrared spectroscopy(FT-IR), and X-ray diffraction(XRD) were applied to study the characteristics of active carbon support and the decomposition of KNO₃ on it. The results revealed that the decomposition temperature of KNO₃ fell into a range of 250℃~400℃ when loaded on active carbon, because of the special interaction between KNO₃ and the surface of active carbon. The XRD results showed that the KO_x base species formedon the surface of KNO₃/AC catalyst after calcination at 500℃ for 4h. Under the optimum reaction conditions of 500℃,0.1MPa,SV＝100 h^-1, and n(C₂F₅H)/n(I₂) =1,the conversion of C₂F₅H over the KNO₃/AC catalyst reached 49.7%, the selectivity of CF₃I achieved 70.5%.

Key words: solid base; potassium nitrate; supported catalyst; active carbon; pentafluoroethane; trifluoroiodomethane

E-mail: lujian204@263.net

Journal of Molecular Catalysis, Vol. 24, Issue 6, 2010, 523~528