نتایج جستجو برای: various catalysts

تعداد نتایج: 797949  

Journal: :Chemical communications 2009
Lukas J Goossen Christophe Linder Nuria Rodríguez Paul P Lange Andreas Fromm

A silver-based catalyst system has been discovered that effectively promotes the protodecarboxylation of various carboxylic acids at temperatures of 80-120 degrees C--more than 50 degrees C below those of the best known copper catalysts.

Journal: :Chemical communications 2003
Naofumi Tsukada Tetsuo Sato Yoshio Inoue

Various allylic alcohols reacted with n-butyl acrylate in the presence of p-toluenesulfonic anhydride and palladium catalysts to yield the corresponding n-butyl 2,5-dienoates with high regioselectivity.

2017
N. R. Shiju D. R. Brown K. Wilson G. Rothenberg

The catalytic dehydration of glycerol to acrolein is investigated over silica-supported niobia catalysts in a continuous fixed-bed gas-phase reactor. Various supported niobia catalysts are prepared and characterized using surface analysis and spectroscopic methods (XRD, UV–Vis, XPS, N2 adsorption), as well as with ammonia adsorption microcalorimetry. Good results are obtained with initial glyce...

Journal: :Topics in current chemistry 2017
Meihui Li Xiyan Liu Xiulan Zhao Feng Yang Xiao Wang Yan Li

Single-walled carbon nanotubes (SWNTs) have shown great potential in various applications attributed to their unique structures and outstanding structure-dependent properties. The structure-controlled growth of SWNTs is a crucial issue for their advanced applications and has been a great challenge in this field for two decades. Metal catalyst-mediated SWNT growth is believed to be very efficien...

Journal: :Organic & biomolecular chemistry 2009
Vincent Coeffard Helge Müller-Bunz Patrick J Guiry

The straightforward preparation of new modular oxazoline-containing bifunctional catalysts is reported employing a microwave-assisted Buchwald-Hartwig aryl amination as the key step. Covalent attachment of 2-(o-aminophenyl)oxazolines and pyridine derivatives generated in good-to-high yields a series of ligands in two or three steps in which each part was altered independently to tune the activi...

2014
Ning Huang Yanhong Xu Donglin Jiang

Protection of metal nanoparticles from agglomeration is critical for their functions and applications. The conventional method for enhancing their stability is to cover them with passivation layers to prevent direct contact. However, the presence of a protective shell blocks exposure of the metal species to reactants, thereby significantly impeding the nanoparticles' utility as catalysts. Here,...

2016
Shahid Ali Khan Sher Bahadar Khan Abdullah M. Asiri

Cd-Al/C layered double hydroxide (Cd-Al/C-LDH) and Cd-Sb/C nanocatalyst are reported here for the de-coloration and mineralization of organic dyes. These catalysts were largely characterized by FESEM, EDS, XRD, FTIR, XPS, PL and DRS. The diffuse reflectance data showed a band gap at 2.92 and 2.983 eV for Cd-Al/C-LDH and Cd-Sb/C respectively. The band gap suggested that both catalysts work well ...

2015
Tetsuo Umegaki Yoshiyuki Kojima Kohji Omata

The effect of oxide coating on the activity of a copper-zinc oxide-based catalyst for methanol synthesis via the hydrogenation of carbon dioxide was investigated. A commercial catalyst was coated with various oxides by a sol-gel method. The influence of the types of promoters used in the sol-gel reaction was investigated. Temperature-programmed reduction-thermogravimetric analysis revealed that...

2014
Ahmad Shamiri Mohammed H. Chakrabarti Shah Jahan Mohd Azlan Hussain Walter Kaminsky Purushothaman V. Aravind Wageeh A. Yehye

50 years ago, Karl Ziegler and Giulio Natta were awarded the Nobel Prize for their discovery of the catalytic polymerization of ethylene and propylene using titanium compounds and aluminum-alkyls as co-catalysts. Polyolefins have grown to become one of the biggest of all produced polymers. New metallocene/methylaluminoxane (MAO) catalysts open the possibility to synthesize polymers with highly ...

2015
Jing Liu Erling Li Mingbo Ruan Ping Song Weilin Xu Minhua Shao

In order to reduce the overall system cost, the development of inexpensive, high-performance and durable oxygen reduction reaction (ORR)N, Fe-codoped carbon-based (Fe/N/C) electrocatalysts to replace currently used Pt-based catalysts has become one of the major topics in research on fuel cells. This review paper lays the emphasis on introducing the progress made over the recent five years with ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید