نتایج جستجو برای: cu based catalyst

تعداد نتایج: 3021400  

2015
Yifei Ma Haegyu Jang Sun Jung Kim Changhyun Pang Heeyeop Chae

Vertical graphene (VG) nanosheets are directly grown below 500 °C on glass substrates by a one-step copper-assisted plasma-enhanced chemical vapour deposition (PECVD) process. A piece of copper foil is located around a glass substrate as a catalyst in the process. The effect of the copper catalyst on the vertical graphene is evaluated in terms of film morphology, growth rate, carbon density in ...

2004
Sittichai Natesakhawat Xueqin Wang Umit S. Ozkan

Hydrogen generation technologies have become increasingly important due to recent attention focusing on fuel cells. The water-gas shift reaction, which is performed in two stages as highand low-temperature shift, is of central significance to produce highpurity hydrogen. Generally, the high-temperature water-gas shift reaction (HTS) is conducted on Fe-Cr catalysts. However, these catalytic syst...

Journal: :Catalysts 2021

Cu-based catalysts are promising for CO oxidation applications with catalyst deactivation being a major barrier. We start CuO/Al2O3 and find that while the conversion decreases, CO2 accumulates average Cu chemical state stays same. It suggests self-poisoning, i.e., desorption is rate-determining step. Subsequently, experiments performed to prove this hypothesis by showing (1) adsorption inhibit...

Journal: :Nanoscale 2013
Pavel Abdulkin Yanina Moglie Benjamin R Knappett David A Jefferson Miguel Yus Francisco Alonso Andrew E H Wheatley

An array of copper and copper-zinc based nanoparticles (NPs) have been fabricated employing a variety of polymeric capping agents. Analysis by TEM, XRPD and XPS suggests that by manipulating reagent, reductant and solvent conditions it is possible to achieve materials that are mono-/narrow disperse with mean particle sizes in the ≤10 nm regime. Oxidative stability in air is achieved for monomet...

Journal: :Chemical communications 2013
Yingchun Ye Lei Wang Shiran Zhang Yuan Zhu Junjun Shan Franklin Feng Tao

A Fe-Cu-Al-O water gas shift catalyst with a Fe : Cu atomic ratio of 4 : 1 upon pretreatment at 350 °C in H2 exhibits a conversion higher than a physical mixture of Fe-Al-O and Cu-Al-O by ~40% over a temperature range of 300 °C-450 °C. In situ ambient pressure X-ray photoelectron spectroscopy studies suggest that the surface region of Fe-Cu-Al-O was restructured into a double-layer structure co...

Journal: :Journal of the American Chemical Society 2009
Debabrata Maiti Stephen L Buchwald

O- or N-arylated aminophenol products constitute a common structural motif in various potentially useful therapeutic agents and/or drug candidates. We have developed a complementary set of Cu- and Pd-based catalyst systems for the selective O- and N-arylation of unprotected aminophenols using aryl halides. Selective O-arylation of 3- and 4-aminophenols is achieved with copper-catalyzed methods ...

2005
Stuart L. Soled Enrique Iglesia

Fe/Zn oxides promoted with K and Cu selectively produce a-olefins at typical FischerTropsch synthesis conditions (2/1 H2/CO, 1 MPa, and 270°C). The simultaneous presence of K and Cu introduces a synergistic activity enhancement while maintaining the high oletrm selectivity obtained by alkali promotion. Structural and morphological differences in Fe-Zn oxides prepared from ammonium glycolate com...

2013
Josė A. Rodriguez Raul Miranda

Current industrial catalysts for the water-gas shift reaction are commonly mixtures of Fe-Cr and Zn-Al-Cu oxides, used at temperatures between 350-500oC and 180250oC, respectively. These oxide catalysts are pyrophoric and normally require lengthy and complex activation steps before usage. Improved catalysts are being sought, particularly for lower temperature (e.g., at T<150oC, equilibrium lowe...

Journal: :Journal of Physical Chemistry C 2022

Methanol synthesis via catalytic CO2 hydrogenation is an important reaction where a valuable fuel and chemical produced from greenhouse gas. In2O3- Pd-promoted In2O3 have experimentally shown promising activity selectivity, although the nature of active sites remains under debate. In this study, kinetic behavior potential in toward methanol competing reverse water–gas shift assessed by explorin...

Journal: :Chinese Journal of Catalysis 2021

Water oxidation is the bottleneck of artificial photosynthesis. Since first ruthenium-based molecular water catalyst, blue dimer, was reported by Meyer's group in 1982, catalysts based on transition metals have been widely employed to explore mechanism oxidation. Because requires harsh oxidative conditions, stability complexes under relevant catalytic conditions has always a challenge. In this ...

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