نتایج جستجو برای: heterogeneous catalysts

تعداد نتایج: 156254  

2017
Jie Miao Jaka Sunarso Chao Su Wei Zhou Shaobin Wang Zongping Shao

Perovskite-like oxides SrCo1-xTixO3-δ (SCTx, x = 0.1, 0.2, 0.4, 0.6) were used as heterogeneous catalysts to activate peroxymonosulfate (PMS) for phenol degradation under a wide pH range, exhibiting more rapid phenol oxidation than Co3O4 and TiO2. The SCT0.4/PMS system produced a high activity at increased initial pH, achieving optimized performance at pH ≥ 7 in terms of total organic carbon re...

Journal: :Inorganic chemistry 2011
Anh Phan Alexander U Czaja Felipe Gándara Carolyn B Knobler Omar M Yaghi

A catalytic system combining the high activity of homogeneous catalysts and the ease of use of heterogeneous catalysts for methane activation is reported. The vanadium-containing metal-organic frameworks (MOFs) MIL-47 and MOF-48 are found to have high catalytic activity and chemical stability. They convert methane selectively to acetic acid with 70% yield (490 TON) based on K(2)S(2)O(8) as an o...

2017
Jun Hu Chaojie Zhu Feifei Xia Zhongxue Fang Fengli Yang Jushi Weng Pengfei Yao Chunzhi Zheng Hai Dong Wenqian Fu

Development of highly active heterogeneous catalysts is an effective strategy for modern organic synthesis chemistry. In this work, acidic mesoporous zeolite ZSM-5 (HZSM-5-M), acidic-free mesoporous zeolite TS-1 (TS-1-M), and basic ETS-10 zeolite supported metal Cu catalysts were prepared to investigate their catalytic performances in the hydroxysulfurization of styrenes with diaryl disulfides....

2017
Yin Zhang Jun Guo Lin Shi Yanfei Zhu Ke Hou Yonglong Zheng Zhiyong Tang

A simple and effective strategy is developed to realize visible light-driven heterogeneous asymmetric catalysis. A chiral organic molecule, which only has very weak catalytic activity in asymmetric α-alkylation of aldehydes under visible light, is utilized as the ligand to coordinate with different types of metal ions, including Zn2+, Zr4+, and Ti4+, for construction of crystalline metal organi...

2013
José M. Fraile José A. Mayoral Nicoletta Ravasio Marta Roldán Laura Sordelli Federica Zaccheria

Copper catalysts supported on silica or silica-alumina are used to promote the insertion of carbenes, coming from methyl phenyldiazoacetate and ethyl diazoacetate, into one C-H bond of THF, constituting the first example of this reaction promoted by a purely inorganic catalyst. Cu/SiO2-Al2O3 leads to better results, regarding yield and catalyst recovery, than with Cu/SiO2. With the former catal...

2012
Diego M. Ruiz Juan C. Autino Nancy Quaranta Patricia G. Vázquez Gustavo P. Romanelli

We report a suitable quinoxaline synthesis using molybdophosphovanadates supported on commercial alumina cylinders as catalysts. These catalysts were prepared by incipient wetness impregnation. The catalytic test was performed under different reaction conditions in order to know the performance of the synthesized catalysts. The method shows high yields of quinoxaline derivatives under heterogen...

2013
Shougo Takahashi Toru Wada Toshiaki Taniike

In heterogeneous Ziegler-Natta catalysts for olefin polymerization, isolation of a single type of active sites is a kind of ambition, which would solve long-standing questions on the relationship between active site and polymer structures. In this paper, polypropylene produced by TiCl3/MgCl2 model catalysts with minimum Ti heterogeneity was analyzed by combined solvent fractionation and the two...

2011
S. Wuttke S. M. Coman J. Kröhnert E. Kemnitz

In this article, the high potential of the fluorolytic sol-gel process to synthesise nanoscopic metal fluorides with different acid-base properties is shown. These nanoscopic materials exhibit high potential to be used as heterogeneous catalysts due to their high surface areas and their tunable surface properties. Thus, for each specific reaction the required surface properties of the catalysts...

2017
Marianna Casavola Jingxiu Xie Johannes D. Meeldijk Nynke A. Krans Andrey Goryachev Jan P. Hofmann A. Iulian Dugulan Krijn P. de Jong

Colloidal synthesis routes have been recently used to fabricate heterogeneous catalysts with more controllable and homogeneous properties. Herein a method was developed to modify the surface composition of colloidal nanocrystal catalysts and to purposely introduce specific atoms via ligands and change the catalyst reactivity. Organic ligands adsorbed on the surface of iron oxide catalysts were ...

2012
Weisheng Liao Ben-Zen Wu Hungchi Nian Hsiang-Yu Chen Jya-Jyun Yu KongHwa Chiu

This article presents the fabrication of size-controllable and shape-flexible microcellular high-density polyethylene-stabilized palladium nanoparticles (Pd/m-HDPE) using supercritical foaming, followed by supercritical impregnation. These nanomaterials are investigated for use as heterogeneous hydrogenation catalysts of biphenyls in supercritical carbon dioxide with no significant surface and ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید