【作者】 蒋成君；

【导师】 尹红； 陈志荣；

【作者基本信息】 浙江大学 ， 工业催化， 2005， 硕士

【摘要】 2,2′—二氯氢化偶氮苯（以下简称DHB）是合成3,3′—二氯联苯胺盐酸盐（以下简称DCB）的中间体。本文通过邻硝基氯苯加氢的方法合成DHB。运用扫描电镜、氮吸附法、全谱等离子发射光谱等方法对催化剂的载体活性炭进行了系统分析,结果表明大比表面、大孔容、大孔径、形貌良好的活性炭较适合本反应体系,而金属杂质的含量对催化剂的影响较小,这为选择、购买催化剂的载体提供了理论依据。对催化剂的制备工艺进行的优化研究结果表明氯铂酸的浓度为0.05625g/ml,pH值在3左右,滴加时间在90分钟时,用甲醛还原的催化剂性能较好,选择性在88%左右,套用次数大于10。选用甲苯为溶剂,25%氢氧化钠水溶液为反应体系,并添加助剂进行加氢反应,DHB的收率可达88%。 本文对邻硝基氯苯加氢动力学进行了研究,在313～343K、0.3～0.6MPa范围内Rideal—Eley历程更好地表现了反应本质,主副反应的本征动力学方程分别为: 主反应 r₁=（（k′₃K₂C_Aa_HP+H）/（1+K₂C_A+K₈C_D）） 副反应 r₂=（（K″₃K₂C_Aa_HP_H）/（1+K₂C_A+K₈C_D）） 其中 k′₃=1.46×10²exp（-2.40×10⁴/RT）min^-1, k″₃=1.35exp（-1.97×10⁴/RT）min^-1, K₂=3.73×10^-3exp（1.84×10⁴/RT）L·mol^-1, K₂·a_H=1.32×10^-2exp（1.13×10⁴/RT）MPa^-1, K₈=2.68×10^-2exp（1.02×10⁴/RT）L·mol^-1 主副反应的活化能分别是24.0和19.7KJ/mol,表明高温有利于提高正反应进行,增加压力也能提高反应速率。更多还原

【Abstract】 2,2’-dichlorohydroazoxybenzene(DHB) is an important commercial interme -diate of 3,3’-dichlorobenzidine(DCB). Synthesis of DHB by hydrogenation of ortho-nitrochlorobenzene is studied in this paper. SEM, nitrogen adsorption and ICP are used to analyze the activated carbon. Platinum catalysts supported on the activated carbon with high purity, large surface area, large pore volume and appropriate pore structure usually exhibit higher activities for hydrogenation of ortho-nitrochlorobenzene to 2,2’-dichlorohydrazobenzene, the content of metal affects less. The process to prepare catalyst is optimized in this paper..The catalyst prepared from 0.05625g/ml H2PtCl6 with pH3 added in 90 minutes shows greater catalytic performance than those prepared under other conditions. The selectivity of the catalyst is 88%, the activity of the recycled catalyst and selectivity to DOB remained constant after 10 runs of recycle.Rideal-Eley course expresses the process better at the temperature from 313-343K and pressure from 0.3~0.6MPa. The intrinsic kinetic is evaluated by simulation of the experimental data, kinetic equations of principal and secondary reactions are as follows:principal reactionsecondary reactionActivation energy is 24.0 kJ/mol and 19.7kJ/mol respectively. Therefore, the temperature of reaction and pressure should be higher.更多还原