硫化Mo/CNT催化剂上甲醇与醋酸甲酯可逆吸附热的测定

本文采用相对保留体积测定了甲醇与醋酸甲酯在碳纳米管载体以及硫化的Mo/CNT催化剂上的可逆吸附热。在碳纳米管载体上,甲醇与醋酸甲酯的可逆吸附热分别为16 0kJ/mol和34 1kJ/mol;在硫化的Mo/CNT催化剂上,甲醇与醋酸甲酯的可逆吸附热分别为15 3kJ/mol和26 1kJ/mol。随温度升高醋酸甲酯的可逆吸附量比甲醇的可逆吸附量下降快,在反应条件下甲醇的可逆吸附量比醋酸甲酯的大8～10倍,甲醇在催化剂上吸附后进行反应,产物醋酸甲酯迅速脱附,从而有利于羰基化反应进行。

Reversible Chemisorption Heat of Methanol and Methyl Acetate on Sulfurized Mo/CNT Catalyst

The reversible chemisorption of methanol and methyl acetate on carbon nanotubes and Mo/CNT catalyst was characterized with relative retention volume and adsorption heat calculated by means of the Clausius-Clapegron relationship. The reversible adsorption heat of methanol on carbon nanotubes and Mo/CNT catalyst is 16.0 kJ/mol and 15.3 kJ/mol, respectively, and that of methyl acetate is 34.1 kJ/mol and 26.1 kJ/mol, respectively. With the increase of temperature, the reversible adsorption amount of methyl acetate was reduced more rapidly than that of methanol. Under the reaction conditions of present study, the reversible adsorption amount of methanol is 8-10 times of that of methyl acetate. After the reaction of adsorptive methanol, methyl acetate, which is the carbonylation product, can desorb rapidly, which is favorable for the reaction of methanol carbonylation.