高比表面积Cr2O3的制备和气相氟化HCFC-133a合成HFC-134a的性能研究

摘要

采用改进溶胶凝胶法合成了高比表面积的Cr2O3催化剂，通过优化实验条件发现，当碳化温度为500℃时，蔗糖与铬摩尔比为2：1，除碳温度为400℃时，制得的Cr2O3比表面积最大（61m^2·g^-1）。合成的高比表面积Cr2O3催化剂气相氟化CF3CH2Cl合成CF3CH3F的催化活性明显高于直接制备的低比表面积Cr2O3催化剂，这归因于高比表面积Cr2O3催化剂具有更多路易斯酸性位。%A high surface area Cr2O3 catalyst was prepared by using a modified sol -gel method. It was found that the optimal conditions for the synthesized of the highest surface area Cr2O3 （m^2·g^-1） are as follows： The temperatures for carbon calcination and carbon removal are 500 ℃ and 400 ℃ respectively, and the molar ratio of sucrose and chromium ion is 1：4. In addition, the high surface area Cr2O3 catalyst was more active for the fluorination of CF3 CH2 C1 to synthesize CF3 CH2 F than the catalyst prepared by a direct synthesis, due to its higher amount of acid sites.