Silica-supported Au@hollow-SiO2 particles with outstanding catalytic activity prepared via block copolymer template approach.
Silica-supported Au@hollow-SiO2 particles with outstanding catalytic activity prepared via block copolymer template approach.
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DOI：
10.1016/j.jcis.2016.12.051
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发表时间：
2017-04
影响因子：
9.9
通讯作者：
A. Shajkumar;Bhanu Nandan;Sunita Sanwaria;V. Albrecht;M. Libera;Myong-Hoon Lee;G. Auffermann;M. Sta
中科院分区：
文献类型：
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作者：
A. Shajkumar;Bhanu Nandan;Sunita Sanwaria;V. Albrecht;M. Libera;Myong-Hoon Lee;G. Auffermann;M. Sta
以聚苯乙烯-聚4-乙烯基吡啶嵌段共聚物为牺牲模板，制备了嵌在多孔二氧化硅载体上的具有催化活性的Au@ hollow-SiO2颗粒（Au@hollow-SiO2@PSS）。热解去除聚合物模板后，观察到壳的孔隙率急剧增加，因为拉伸的聚（4-乙烯基吡啶）链与二氧化硅壳的互穿作为一个有效的致孔剂。Au@ hollow-SiO2颗粒在多孔二氧化硅载体中的嵌入防止了它们在热解过程中的熔融。以对硝基苯酚的催化还原和刚果红偶氮染料的还原降解为模型反应，研究了Au@hollow-SiO2@PSS的催化活性。值得注意的是，据我们所知，Au@hollow-SiO2@PSS催化剂在文献中迄今报道的类似体系中显示出最高的活性。这种高活性归因于Au@ hollow-SiO2颗粒的二氧化硅壳层内存在多个孔，并且试剂容易通过多孔二氧化硅载体到达无配体的金表面的催化活性位点。
Catalytically active Au@hollow-SiO2particles embedded in porous silica support (Au@hollow-SiO2@PSS) were prepared by using spherical micelles from poly(styrene)-block-poly(4-vinyl pyridine) block copolymer as a sacrificial template. Drastic increase of the shell porosity was observed after pyrolytic removal of polymeric template because the stretched poly(4-vinyl pyridine) chains interpenetrating with silica shell acted as an effective porogen. The embedding of Au@hollow-SiO2particles in porous silica support prevented their fusion during pyrolysis. The catalytic activity of Au@hollow-SiO2@PSS was investigated using a model reaction of catalytic reduction of 4-nitrophenol and reductive degradation of Congo red azo-dye. Significantly, to the best of our knowledge, Au@hollow-SiO2@PSS catalyst shows the highest activity among analogous systems reported till now in literature. Such high activity was attributed to the presence of multiple pores within silica shell of Au@hollow-SiO2particles and easy accessibility of reagents to the catalytically active sites of the ligand-free gold surface through the porous silica support.