Unravelling mass transport in hierarchically porous catalysts
Unravelling mass transport in hierarchically porous catalysts
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DOI：
10.1039/c9ta01867k
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发表时间：
2019-05-21
影响因子：
11.9
通讯作者：
Lee, Adam F.
中科院分区：
文献类型：
--
作者：
Isaacs, Mark A.;Robinson, Neil;Lee, Adam F.
生物衍生平台化学品和燃料对于可持续制造业的发展非常重要。然而，它们从生物质的有效生产需要新的催化剂和优化的大分子的选择性转化过程。介孔和分级多孔功能材料是有前途的催化剂候选生物质价值，但孔尺寸/连通性，质量传递，和相应的催化性能之间的定量关系定义不清。制备了一系列具有可调大孔直径的多级孔-介孔SBA-15磺酸，用于羧酸酯化反应。周转率为长链（棕榈酸和芥酸）酸成正比的大孔直径（370 nm），而丙酸酯化是独立的大孔尺寸。脉冲场梯度NMR扩散实验表明，较大的大孔通过赋予上级孔互连性和相关的质量传递来增强大体积羧酸的酯化。
Bio-derived platform chemicals and fuels are important for the development of sustainable manufacturing. However, their efficient production from biomass necessitates new catalysts and processes optimised for the selective transformation of large molecules. Mesoporous and hierarchically porous functional materials are promising catalyst candidates for biomass valorisation, but quantitative relationships between pore dimensions/connectivity, mass transport, and corresponding catalytic performance are poorly defined. A family of hierarchical macroporous-mesoporous SBA-15 sulfonic acids were prepared with tunable macropore diameters for carboxylic acid esterification. Turnover frequencies for long-chain (palmitic and erucic) acids were proportional to macropore diameter (370 nm), whereas propanoic acid esterification was independent of macropore size. Pulsed field gradient NMR diffusion experiments reveal that larger macropores enhance esterification of bulky carboxylic acids by conferring superior pore interconnectivity and associated mass transport.