铜基催化剂的制备方法对草酸二乙酯加氢反应的影响

草酸二乙酯加氢性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ＴＭ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＾ｏ和Ｃｕ＾＋两种价态。结合活性评

EFFECT OF THE PREPARATION OF Cu-BASED CATALYST ON THE HYDROGENATION OF DIETHYL OXALATE

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.