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在633～673K,用氢作载气,通过曲线拟合测得了3-氯甲苯在LaPO_4-Cu和LaPO_4催化剂上常压水解的初始反应速率,得到了经验速率方程和动力学方程,并求出了有关参数。发现微量铜助剂对3-氯甲苯的吸附系数b_A影响不大,却使表面反应速率常数比原来LaPO_4提高约26倍;产物HCl的吸附系数b_c特别大,比b_A大11倍,因此对水解反应速率有很大的阻抑作用。结合催化剂表面酸性的程序升温脱附考察结果,推断水吸附在L酸中心,3-氯甲苯主要吸附在B酸中心,表面反应为速率控制步骤。在LaPO_4-Cu上,3-氯甲苯的吸附热为68.2KJ/mol,表面反应的活化能为213.6KJ/mol。数据处理和参数确定均用最小二乘回归法。
The initial reaction rate of 3-chlorotoluene hydrolysis on LaPO_4-Cu and LaPO_4 catalysts was measured by curve fitting at 633 ~ 673K using hydrogen as the carrier gas. The empirical rate equation and kinetic equation were obtained and obtained The relevant parameters. It was found that trace copper additives had little effect on the adsorption coefficient b_A of 3-chlorotoluene, but the surface reaction rate constant was about 26 times higher than that of the original LaPO_4. The adsorption coefficient of product HCl was particularly large, which was 11 times larger than that of b_A, The reaction rate has a great inhibitory effect. According to the results of temperature programmed desorption on the surface of catalyst, it is inferred that water is adsorbed on the center of L acid and 3-chlorotoluene is mainly adsorbed on the center of B acid. The surface reaction is the rate control step. On LaPO 4-Cu, the adsorption heat of 3-chlorotoluene is 68.2KJ / mol and the activation energy of the surface reaction is 213.6KJ / mol. Data processing and parameters are determined by least squares regression.