银催化剂上丁二烯环氧化宏观反应动力学的研究

Kinetic Study on Butadiene Epoxidation over Ba, Cs and Cl Promoted Ag/Al_2O_3 Catalyst

考察了在Ba-Cs-Cl-Ag/α-Al2O3上以空气为氧化剂的丁二烯气相环氧化反应条件对催化剂性能的影响.宏观动力学实验结果表明,依据Langmuir-Hinselwood机理推测的动力学表达式与实验结果吻合较好,幂函数型的动力学表达式给出了在低丁二烯分压下,丁二烯的反应级数为1.9,O2的反应级数为1.1.丁二烯转化、生成乙烯基环氧乙烷及生成CO2的表观活化能分别为55.4kJ/mol、54.8kJ/mol和64.6kJ/mol.

Using air as oxidant, the effects of reaction conditions on performance of Ba, Cs, Cl promoted Ag/α-Al2O3 catalysts for butadiene epoxidation were examined. Kinetic studies showed that expressions based on a dual-site Langmuir-Hinselwood mechanism well fitted the experimental data. The apparent activation energies for the epoxidation, and combustion reactions were 55.4 and 64.6 kJ/mol, respectively. The kinetic expression of exponential function model suggested that butadiene and oxygen reaction orders were 1.9 and 1.1, respectively under lower butadiene partial pressure.