山西省基础研究计划(自由探索类)青年基金项目(202103021223323, 202103021223326, 20210302124343)；国家自然科学基金项目(22075167)
This work is supported by Shanxi Provincial Basic Research Program (Free Exploration) Youth Fund (202103021223323, 202103021223326, 20210302124343), and National Natural Science Foundation of China (22075167)
开发高效的 Ni 基加氢催化剂，实现 1,4-丁炔二醇加氢定向合成 1,4-丁二醇，是构建煤基初级化学品高值化延伸产业链的关键。针对目前广泛采用的 Raney Ni 催化剂，无载体支撑，存在活性比表面低、加氢选择性差等问题，该文制备了以发达孔隙结构的活性炭(active carbon，AC)为载体的 Ni/AC 催化剂，结合表征手段探讨了催化剂结构与性能的构效关系。研究结果表明，随着 Ni 负载量的升高，活性炭表面暴露的活性镍物种先增加后减少，加氢活性也呈火山形分布。25Ni/AC(Ni 的质量分数为 25%)催化剂对 1,4-丁二醇的选择性最高，达 86.2%，对半加氢产物 1,4-丁烯二醇与半缩醛 2-羟基四氢呋喃的选择性分别为 1.2% 与 6.8%。造成此现象的原因是该样品中高分散的活性 Ni 提供了大量活性氢，促进了加氢反应。低 Ni 负载量的催化剂因 Ni 活性中心间距较远，表面活性 H 密度低，而易于发生异构副反应生成半缩醛 2-羟基四氢呋喃。当 Ni 负载量较高时，Ni 聚集造成加氢活性下降。
Developing efficient Ni based hydrogenation catalysts to achieve the directional synthesis of 1,4-butanediol from 1,4-butynediol hydrogenation is the keypoint to building a high value extension industrial chain for coal based primary chemicals. Aiming at solving the problems of Raney Ni catalyst widely used at present, such as lacking support, low activity specific surface area, and poor hydrogenation selectivity, a Ni/ AC catalyst with well-developed pore structure activated carbon (AC) as support was prepared in this work, and the structure-activity relationship between catalyst structure and performance was discussed by combining characterization methods. The results showed that with the increase of Ni loading, the active nickel species exposed on the activated carbon surface increased at first and decreased later, and the hydrogenation activity also show as volcanic distribution. The 25% Ni/AC catalyst loaded with 25% Ni had the highest selectivity of 1,4-butanediol, reaching 86.2%. At this time, the selectivity of 1,4-butenediol and 2-hydroxytetrahydrofuran, the semi hydrogenation products, were 1.2% and 6.8%, respectively. Due to the highly dispersed active Ni species in this sample, a large amount of active hydrogen is provided, which promotes the hydrogenation reaction. Due to the long distance between Ni active centers and the low density of surface active H on catalysts with low Ni loading, isomerization side reactions are prone to occur to generate 2-hydroxytetrahydrofuran. At high Ni loading, the aggregation of Ni species results in the decrease of hydrogenation activity.
高 洁,常骋昊,吕冰佳,等. Ni/AC 催化剂的制备、表征与 1,4- 丁炔二醇加氢性能 [J].集成技术,2023,12(6):83-92
GAO Jie, CHANG Chenghao, LV Bingjia, et al. Preparation, Characterization and Catalytic Performance of Ni/AC Catalyst for 1,4-butynediol Hydrogenation[J]. Journal of Integration Technology,2023,12(6):83-92