Frozen slurry catalytic reactor: A new structured catalyst for transient studies in liquid phase
Frozen slurry catalytic reactor: A new structured catalyst for transient studies in liquid phase
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DOI：
10.1016/j.apcata.2008.09.011
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发表时间：
2008-12
影响因子：
5.5
通讯作者：
D. Radivojević;M. Avramescu;K. Seshan;Matthias Wessling;L. Lefferts
中科院分区：
文献类型：
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作者：
D. Radivojević;M. Avramescu;K. Seshan;Matthias Wessling;L. Lefferts
在这项研究中，我们提出了一种通过浸没相分离将单分散的铂/二氧化硅催化剂颗粒引入EVAL聚合物多孔基质中来制备催化聚合物膜的方法。添加相对较高浓度(65wt%)的催化剂颗粒可防止形成大孔洞，提高膜的机械稳定性以及改善通过膜的液体流量分布的均匀性。催化剂颗粒在制备过程中保持不变。催化剂颗粒在整个膜中被物理固定，被困在孔中，防止当流经等效的浅固定床时发生的沟道。此外，与具有相同直径和相同数量的催化剂颗粒的固定床相比，这种新颖的冻结浆体状形态导致了显著较低的压降。低压降，尽管载体颗粒尺寸很小，但对于在液相中操作新的瞬变方法来说，是一个重要的技术优势。铂颗粒在溶胀状态下(即在液体中)是非常容易获得的，载铂/二氧化硅薄膜对葡萄糖氧化的催化活性以及观察到的H2-O2滴定证实了接近所有铂表面原子的贡献。
In this study we present a method to prepare catalytic polymer membranes by incorporating mono-dispersed Pt/SiO2catalyst particles in an EVAL polymer porous matrix via immersion phase separation. Addition of a relatively high concentration (65wt%) of catalyst particles is preventing the formation of macro-voids, improving both mechanical stability of the membranes as well as improving homogeneity of the liquid flow distribution through the membrane. The catalyst particles remain intact during the preparation procedure. The catalyst particles are physically immobilized throughout the membrane, entrapped in the pores, preventing channeling that would occur when flowing through an equivalent shallow fixed bed. Furthermore, the novel frozen-slurry-like morphology results in significant lower pressure drop as compared to a fixed bed with identical diameter and containing the same amount of catalyst particles. Low pressure drop, despite very small support particle size, is an important technical advantage for operating a new transient method in liquid phase. The platinum particles are proven to be highly accessible in the swollen state, i.e. in liquid phase, as demonstrated both by the catalytic activity of the Pt/SiO2loaded membranes for glucose oxidation as well as by the observation that H2–O2titrations confirms that close to all platinum surface atoms contribute.