碱助剂促进Ni基催化剂氢解山梨醇制备二元醇

采用逐步湿浸渍的方法制备了一系列含有不同载体和碱促进剂的Ni基催化剂用于生物质基平台化合物山梨醇的氢解反应. 通过反应对载体和碱促进剂进行了筛选和组分含量的优化，碱性促进剂的引入不仅增强了催化剂的碱性，而且通过Ni²⁺和碱促进剂的强相互作用提高了Ni在催化剂上的分散性；10%Ni/10%La₂O₃/ZrO₂表现出了非常高的氢解活性和较好的二元醇(乙二醇和1,2丙二醇)选择性，金属Ni和碱促进剂La₂O₃之间的协同作用机理对于山梨醇选择性氢解制备二元醇影响显著. 在优化的反应条件下，山梨醇达到100%的转化并且有超过48%的二元醇产率. 研究中对催化剂进行了XRD、BET、H₂-TPR和CO₂-TPD表征，用于分析催化剂结构性能. 通过对山梨醇氢解以及中间产物动力学曲线的研究，得出多元醇氢解活性与所含羟基数正相关，产物的最终分布是氢解动力学平衡的最终结果.

Sorbitol Hydrogenolysis to Glycols over Baisic Additive Promoted Ni-based Catalysts

A series of Ni based catalysts with different supports and basic additives were prepared by sequential impregnation method. The catalysts were characterized by XRD, BET, H₂-TPR and CO₂-TPD techniques. It was found that the introduction of basic additives enhanced the basicities of catalyats and promoted the dispersities of Ni particles by strong interaction between Ni²⁺ and basic additives. Among the Ni based catalysts, 10%Ni/10%La₂O₃/ZrO₂ showed the superior performance in sorbitol hydrogenolysis. The synergistic effect of Ni and La₂O₃ was proven to play an essential role in selective synthesis of EG and 1,2-PG. In the optimal reaction condition, the catalyst presented 100% sorbitol conversion and over 48% glycols (EG and 1,2-PG) yield. The kinetics study of polyols (sorbitol, xylitol and glycerol) hydrogenolysis showed that polyols with more hydroxyl number have higher activity and products distribution was final results of kinetic balance, which could give us some inspiration about how to change the products selectivity.