The preparation of high-surface-area Pt/SiO2 catalysts with well-defined pore size distributions
The preparation of high-surface-area Pt/SiO2 catalysts with well-defined pore size distributions
复制标题
具有明确孔径分布的高比表面积 Pt/SiO2 催化剂的制备
DOI：
10.1006/jcat.1995.1083
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发表时间：
1995
影响因子：
7.3
通讯作者：
R. González
中科院分区：
文献类型：
--
作者：
W. Zou;R. González
通过匹配金属颗粒的大小和平均孔径，可以制备出热稳定性较好的负载型金属催化剂。提出了实现这场比赛的准备变量。在pH值为3~8的范围内，用正硅酸乙酯(TEOS)制备的空白二氧化硅凝胶具有350~800m{sup2}/g的比表面积和4~25 nm的中孔结构，Hsub2O/TEOS比值为10。二氧化硅气凝胶具有与干凝胶相当的比表面积、更大的孔径和孔容。以Sol-Gel法制备的负载型铂催化剂为例，考察了金属前驱体、金属负载量、反应物化学计量比、溶剂脱除等制备条件对催化剂性能的影响。在合成过程中，通过调节H{sub2}O/TEOS的比例，铂(Acac){sub2}催化剂的平均孔径可在4-20 nm范围内变化。较好的比表面积为500~800m/g，金属分散度为50~85%。研究了这些催化剂上的H{sub2}/正己烷反应。催化活性与传统方法制备的负载型金属催化剂相当或略有提高。参考文献26，图10，表11。
Thermally stable supported metal catalysts can be prepared by matching the metal particle size to the average pore diameter. Preparative variables aimed at achieving this match are presented. In the 3-8 pH range, blank silica gels prepared using tetraethoxysilane (TEOS) were observed to have BET surface areas of 350-800 m{sup 2}/g and mesoporous structures with an average pore diameter of between 4 and 25 nm at a constant H{sub 2}O/TEOS ratio of 10. Silica aerogels have comparable BET surface areas, larger pore diameters, and pore volumes than xerogels. In the case of supported Pt catalysts prepared by sol-gel synthesis, the effect of preparative variables, including metal precursor, metal loading, reactant stoichiometries, and solvent removal, have been studied. The use of Pt(AcAc){sub 2} resulted in average pore diameters which could be varied in the 4-20-nm range by adjusting the H{sub 2}O/TEOS ratio during synthesis. BET surface areas in the 500-800 m{sup 2}/g and metal dispersions of 50-85% can be achieved. The H{sub 2}/n-hexane reaction was studied on these catalysts. Catalytic activities were found to be comparable or slightly superior to supported metal catalysts prepared by traditional methods. 26 refs., 10 figs., 11 tabs.