Hierarchically Ordered Nanoporous Pd/SBA-15 Catalyst for the Aerobic Selective Oxidation of Sterically Challenging Allylic Alcohols
Hierarchically Ordered Nanoporous Pd/SBA-15 Catalyst for the Aerobic Selective Oxidation of Sterically Challenging Allylic Alcohols
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DOI：
10.1021/cs400371a
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发表时间：
2013-09-01
期刊：
影响因子：
12.9
通讯作者：
Lee, Adam F.
中科院分区：
文献类型：
--
作者：
Parlett, Christopher M. A.;Keshwalla, Pooja;Lee, Adam F.
示出了包括270 nm大孔和5 nm中孔（MM-SBA-15）的分级有序纳米多孔SBA-15结构用于空间上具有挑战性的烯丙醇的催化有氧选择性氧化的效用。详细的本体和表面表征表明，将互补的大孔到介孔SBA-15中增强了亚2 nm Pd纳米粒子的分散，从而提高了它们的表面氧化程度。动力学分析揭示了纳米颗粒分散和氧化速率之间的关系，确定表面PdO的催化活性相。分级纳米多孔Pd/MM-SBA-15在烯丙醇选择性氧化中优于介孔类似物，其通过（i）稳定PdO纳米颗粒和（ii）显著改善孔内扩散和倍半萜类底物（如法呢醇和植醇）对活性位点的访问。
The utility of a hierarchically ordered nanoporous SBA-15 architecture, comprising 270 nm macropores and 5 nm mesopores (MM-SBA-15), for the catalytic aerobic selective oxidation of sterically challenging allylic alcohols is shown. Detailed bulk and surface characterization reveals that incorporation of complementary macropores into mesoporous SBA-15 enhances the dispersion of sub 2 nm Pd nanoparticles and thus their degree of surface oxidation. Kinetic profiling reveals a relationship between nanoparticle dispersion and oxidation rate, identifying surface PdO as the catalytically active phase. Hierarchical nanoporous Pd/MM-SBA-15 outperforms mesoporous analogues in allylic alcohol selective oxidation by (i) stabilizing PdO nanoparticles and (ii) dramatically improving in-pore diffusion and access to active sites by sesquiterpenoid substrates such as farnesol and phytol.