Enhanced Activity and Selectivity in the One-Pot Hydroxylation of Phenol by Pd/SiO2@Fe-Containing Mesoporous Silica Core–Shell Catalyst
Enhanced Activity and Selectivity in the One-Pot Hydroxylation of Phenol by Pd/SiO2@Fe-Containing Mesoporous Silica Core–Shell Catalyst
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DOI：
10.1021/jp411153p
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发表时间：
2014-01
影响因子：
3.7
通讯作者：
Shohei Ikurumi;Shusuke Okada;Kazuki Nakatsuka;T. Kamegawa;K. Mori;H. Yamashita
中科院分区：
文献类型：
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作者：
Shohei Ikurumi;Shusuke Okada;Kazuki Nakatsuka;T. Kamegawa;K. Mori;H. Yamashita
研究了一种新的提高苯酚一锅法羟基化合成邻苯二酚和对苯二酚的催化性能的方法，该方法采用核-壳型催化剂，由用于H2和O2直接合成H2 O2的Pd纳米颗粒（NPs）和用于原位生成H2 O2的苯酚羟基化的含铁介孔氧化硅（Fe-MS）组成。我们新制备了三种类型的核-壳催化剂：（i）用Fe-MS覆盖的Pd/SiO2芯（Pd/SiO2@Fe-MS），（ii）SiO2核被Fe-MS覆盖，在介孔二氧化硅结构内具有随机分布的Pd NP（SiO2@Pd（R）/Fe-MS），其中（R）表示随机，和（iii）被Fe-MS覆盖的SiO2核，其中Pd NP沉积在中孔SiO2@Pd（S）/Fe-MS的外表面上，其中（S）表示表面。考察了Pd NPs与Fe-MS的相对位置对催化活性和选择性的影响。结果表明，相对位置不仅对反应速率有显著影响，而且对反应速率也有显著影响。
A novel approach to enhance the catalytic performances in one-pot hydroxylation of phenol into catechol and hydroquinone was examined using core–shell type catalysts which consist of Pd nanoparticles (NPs) for direct synthesis of H2O2 from H2 and O2 and Fe-containing mesoporous silica (Fe-MS) for hydroxylation of phenol using in situ produced H2O2. We have newly prepared three types of core–shell catalysts: (i) Pd/SiO2 core covered with Fe-MS (Pd/SiO2@Fe-MS), (ii) SiO2 core covered by Fe-MS with randomly distributed Pd NPs within the mesoporous silica structure (SiO2@Pd(R)/Fe-MS), where (R) indicates random, and (iii) SiO2 core covered by Fe-MS with Pd NPs deposited on the outer surface of the mesopores SiO2@Pd(S)/Fe-MS, where (S) indicates the surface. The effects of the relative position between the Pd NPs and Fe-MS on the catalytic activity and the selectivity were investigated. As a result, it was clearly demonstrated that the relative position significantly affects not only the reaction rate but also...