Functional Nanomaterials Laboratory, Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences, Zhongguancundonglu 29, Haidianqu, Beijing, 100190, China.
Nanoscale. 2012 Feb 7;4(3):852-9. doi: 10.1039/c1nr11504a. Epub 2011 Dec 16.
Our previously fabricated amino-functionalized silica nanoparticles (NPs) with center-radially hierarchical mesopores (NH(2)-HMSNs) were purified by a filtration membrane and used as catalyst carriers in the current article. Noble metal NPs (Au, Pd, Pt and Au & Pt) with small sizes (3-8 nm) were successfully immobilized into the NH(2)-HMSNs via the deposition-precipitation method. These noble metal NPs with readily adjusted small sizes have high density and well-dispersed distribution on the surface of large mesopores of NH(2)-HMSNs. Among them, Au-NH(2)-HMSNs were investigated as the composite catalyst in the catalytic reduction of 2-nitroaniline (2-NA) as a model reaction and exhibited excellent catalytic activity and stability. The presence of center-radially large mesopores in the NH(2)-HMSNs may favor the loading of noble metal NPs with high density and well-dispersed distribution on the surface of large mesopores of NH(2)-HMSNs. Metal-NH(2)-HMSNs may be more promising composite catalysts due to their superstructure of center-radially hierarchical mesopores that maybe significantly enhance and harmonize the diffusion of guest molecules of different sizes through the porous matrices.
我们之前制备的具有中心-径向分级介孔（NH(2)-HMSNs）的氨基功能化硅纳米粒子（NPs）通过滤膜进行了纯化，并在本文中用作催化剂载体。通过沉积-沉淀法成功地将小尺寸（3-8nm）的贵金属 NPs（Au、Pd、Pt 和 Au & Pt）固定在 NH(2)-HMSNs 中。这些可调节尺寸的贵金属 NPs 在 NH(2)-HMSNs 的大介孔表面上具有高密度和良好的分散分布。其中，Au-NH(2)-HMSNs 被用作催化还原 2-硝基苯胺（2-NA）的复合催化剂，表现出优异的催化活性和稳定性。NH(2)-HMSNs 中的中心-径向大介孔的存在可能有利于高密度和良好分散的贵金属 NPs 在 NH(2)-HMSNs 的大介孔表面上的负载。由于其具有中心-径向分级介孔的超结构，金属-NH(2)-HMSNs 可能是更有前途的复合催化剂，这可能显著增强和协调不同尺寸客体分子通过多孔基质的扩散。
