液相还原法制备新型Ru/C催化剂的研究

Study on Preparation of a Noveo Ru/C Catalysts by Liquid Reducation Method

用正交实验考察了溶液温度、pH值、搅拌速度等因素对催化剂吸附量的影响规律,并据此用浸渍及甲醛还原法制备了系列Ru/C催化剂,在0.5MPa、120℃下测得葡萄糖加氢生成山梨醇的催化活性、山梨醇选择性和催化剂的稳定性。并运用程序升温还原TPR(temperature programmed reduction)技术研究了催化剂的表面还原性质。结果表明:钌的负载量对Ru/C催化剂的性能影响较大,钌负载量为5%时,制得的催化剂具有较佳的各项性能。钌的负载量越少时,负载钌的分散度越高,钌与载体间作用力越强,催化剂的还原温度越高。同时,随着含钌量的增加,催化剂的还原峰发生明显的变化,负载量为5%时出现了明显的肩峰,化学吸附是催化活性的主要来源。

The influences of various factors such as solution temperature, pH value, slurring speed etc. on catalyst absorption quantity were studied adopting the orthogonal design, based on which a series of Ru/C catalysts were prepared by the impregnation process and the chemical reduction with HCHO solution. The catalyst activity and selection of the sorbitol as well as the catalyst stability were tested under 0.5 MPa and at 120℃. The surface reduction characteristics of the catalysts were studied by TPR （temperature programmed reduction）. The results show that Ru loading content has a great effect on the property of Ru/C catalyst. Upon 5% of Ru loading content, the prepared catalyst has better properties. The less the Ru loading content, the higher the catalyst reduction temperature. While further in creasing the Ru loading content, the obvious change of the reduction peak of the catalyst would take place, and a shoulder-shaped peak appeared upon 5% of Ru loading content. Chemical absorption originates mainly from the catalyst activity.