【摘要】 草酸二乙酯加氢生成乙二醇的反应过程中。所用的铜基催化剂是由Cu（NO₃）₂与硅溶胶胶凝法制得的.本文考察了该催化剂的TPR特性,结果表明.随着催化剂中Cu/ SiO₂值的增大.其TPR主峰T_m峰温有所升高.这意味着催化剂的还原温度随Cu/SiO₂值的增大而提高.用XRD和XPS等手段对该催化剂还原后铜的含量及价态进行了考察.表明用胶凝法制备的铜基催化剂,还原后存在Cu～0 和Cu～- 两种价态.结合活性评价结果.证明Cu～-决定着反应物的转化率,而Cu～0 则决定着乙二醇的选择性.更多还原

【Abstract】 The Cu/SiO2 catalyst was made with precipitation method. Cupric nitrate was dissolved in deionized water and ammonia water was slowly added to the solution until the pH reached 9, resulting the indigo-blue cuprammonia complex solution while stirring and heating, then adding silica gel solution subsequently to form gelatinous precipitate. The precipitate was washed and dried. The range of Cu/SiO2 value in the catalyst was from 0. 01 to 1. 0. The catalyst was used for hydrogenation of diethyl oxalate to ethylene glycol. The technique of temperature programmed reduction (TPR) was used to study the Cu-based catalyst. The main peak T(M) of TPR of the catalyst grew with the increase of Cu/ SiO2. The techniques of XRD and XPS were used to study the situation of copper in the catalyst before and after reduction. According to the results of the activity evaluation, the following conclusions were obtained: Cu~+ is a decisive factor for the conversion of diethyl oxalate and Cu~0 is one for the selectivity for ethylene glycol.更多还原