Morphological effects of ordered Cr 2 O 3 nanorods and Cr 2 O 3 nanoparticles on fluorination of 2-chloro-1,1,1-trifluoroethane
Journal of Materials Science(2016)
摘要
Ordered Cr 2 O 3 nanorods (Cr 2 O 3 -R) and Cr 2 O 3 nanoparticles (Cr 2 O 3 -P) were prepared by a hard template method with SBA-15 and a deposition–precipitation method, respectively. These catalysts were tested for the fluorination of 2-chloro-1,1,1-trifluoroethane (HCFC-133a) to synthesize 1,1,1,2-tetrafluoroethane (HFC-134a). It was found that both catalysts were very selective, with a HFC-134a selectivity of 98 %. However, the Cr 2 O 3 -R catalyst had an area specific reaction rate of 0.012 μmol m −2 s −1 at 320 °C, which was much higher than that on the Cr 2 O 3 -P (0.005 μmol m −2 s −1 ). The enhanced activity of the Cr 2 O 3 -R was attributed to its higher content of Cr(VI) species compared to that in the Cr 2 O 3 -P, which was evidenced by the hydrogen temperature-programmed reduction and X-ray photoelectron spectroscopy results. Besides, the Cr 2 O 3 -R catalyst had a higher surface acid density (0.076 mmol m −2 ) than the Cr 2 O 3 -P (0.068 mmol m −2 ), which could be another reason for its better performance.
更多查看译文
关键词
BiVO4, Specific Reaction Rate, Trifluoroethane, Mesoporous Metal Oxide, Hard Template Method
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络