| 查看: 20895 | 回复: 718 | ||||
| 本帖产生 2 个 MN-EPI ，点击这里进行查看 | ||||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | ||||
xiejf专家顾问 (文学泰斗)
|
[资源]
Acc. Chem. Res.最新综述：核-壳结构纳米催化剂
|
|||
|
最新一期的Acc. Chem. Res.刊发了由美国加利福尼亚大学河滨分校殷亚东教授课题组撰写的题为Core–Shell Nanostructured Catalysts的研究性综述，主要讲述了核壳结构的制备，形成机理以及进展，并着重介绍了核壳纳米结构作为催化剂的优势以及研究进展。文章9页，引文44篇。 Novel nanotechnologies have allowed great improvements in the syn-thesis of catalysts with well-controlled size, shape, and surface properties. Transition metal nanostructures with specific sizes and shapes, for instance, have shown great promise as catalysts with high selectivities and relative ease of recycling. Researchers have already demonstrated new selective catalysis with solution-dispersed or supported-metal nanocatalysts, in some cases applied to new types of reactions. Several challenges remain, however, particularly in improving the structural stability of the catalytic active phase. Core–shell nanostructures are nanoparticles encapsulated and protected by an outer shell that isolates the nanoparticles and prevents their migration and coalescence during the catalytic reactions. The synthesis and characterization of effective core–shell catalysts has been at the center of our research efforts and is the focus of this Account. Efficient core–shell catalysts require porous shells that allow free access of chemical species from the outside to the surface of nanocatalysts. For this purpose, we have developed a surface-protected etching process to prepare mesoporous silica and titania shells with controllable porosity. In certain cases, we can tune catalytic reaction rates by adjusting the porosity of the outer shell. We also designed and successfully applied a silica-protected calcination method to prepare crystalline shells with high surface area, using anatase titania as a model system. We achieved a high degree of control over the crystallinity and porosity of the anatase shells, allowing for the systematic optimization of their photocatalytic activity. Core–shell nanostructures also provide a great opportunity for controlling the interaction among the different components in ways that might boost structural stability or catalytic activity. For example, we fabricated a SiO2/Au/N-doped TiO2 core-shell photocatalyst with a sandwich structure that showed excellent catalytic activity for the oxidation of organic compounds under UV, visible, and direct sunlight. The enhanced photocatalytic efficiency of this nanostructure resulted from an added interfacial nonmetal doping, which improved visible light absorption, and from plasmonic metal decoration that enhanced light harvesting and charge separation. In addition to our synthetic efforts, we have developed ways to evaluate the accessibility of reactants to the metal cores and to characterize the catalytic properties of the core–shell samples we have synthesized. We have adapted infrared absorption spectroscopy and titration experiments using carbon monoxide and other molecules as probes to study adsorption on the surface of metal cores in metal oxide–shell structures in situ in both gas and liquid phases. In particular, the experiments in solution have provided insights into the ease of diffusion of molecules of different sizes in and out of the shells in these catalysts. .  1.jpg  2.jpg [ 来自科研家族 材料家族 ] |
回复此楼» 本帖附件资源列表
-
欢迎监督和反馈：小木虫仅提供交流平台，不对该内容负责。
本内容由用户自主发布，如果其内容涉及到知识产权问题，其责任在于用户本人，如对版权有异议，请联系邮箱：libolin3@tal.com - 附件 1 : Core–ShellNanostructuredCatalysts.pdf
2012-12-27 10:16:21, 1.08 M
» 本帖已获得的红花（最新10朵）
熊熊--123» 猜你喜欢
广东以理材料系碳点与功能材料课题组 — 2博士名额 / 科研助理
已经有11人回复
-
24考博孤注一掷，寄在了复试，但是还是想上一个学
已经有39人回复
-
无机化学论文润色/翻译怎么收费?
已经有176人回复
-
P4VP的GPC测试
已经有3人回复
-
求购商用高炉煤气精脱硫水解催化剂
已经有36人回复
» 本主题相关商家推荐: (我也要在这里推广)
99楼2012-12-29 09:00:01
简单回复
bwiner2楼
2012-12-27 10:26
回复
五星好评 顶一下，感谢分享！
鲤鱼lee3楼
2012-12-27 10:29
回复
五星好评 顶一下，感谢分享！
xzb3284楼
2012-12-27 10:32
回复
五星好评 顶一下，感谢分享！
hpcqq5楼
2012-12-27 10:36
回复
五星好评 顶一下，感谢分享！
2012-12-27 11:17
回复
五星好评 顶一下，感谢分享！
skyfly8楼
2012-12-27 11:39
回复
五星好评 顶一下，感谢分享！
2012-12-27 11:41
回复
五星好评 顶一下，感谢分享！
vgiant198810楼
2012-12-27 12:01
回复
五星好评 顶一下，感谢分享！
cwsl712楼
2012-12-27 12:28
回复
五星好评 顶一下，感谢分享！
xuefei271613楼
2012-12-27 12:31
回复
五星好评 顶一下，感谢分享！
xiachemistry14楼
2012-12-27 12:32
回复
五星好评 顶一下，感谢分享！
10