نتایج جستجو برای: catalyst

تعداد نتایج: 44027  

2008
Jing Fang Ranjan Jana Jon Tunge Bala Subramaniam

Introduction Industrial higher olefin (> C5) hydroformylation processes require harsh temperatures and pressures (140 200 oC, 5 30 MPa) as well as tedious catalyst separation schemes involving hazardous reagents to recycle the cobalt catalyst [1]. The use of rhodium (Rh) as a catalyst would lower the operating temperature and pressure but requires almost quantitative recovery and recycle of the...

2006
Wei Liu

The catalyst activity of fluorite-type oxide, such as ceria and zirconia, for the reduction of sulfur dioxide by carbon monoxide to elemental sulfur can be significantly promoted by active transition metals, such as copper. More than 95% elemental sulfur yield, corresponding to almost complete sulfur dioxide conversion, was obtained over a Cu-Ce-O oxide catalyst with a feed gas of stoichiometri...

2016
Ryo Shirai Masanori Hayase

A novel catalyst layer structure is proposed for our miniature fuel cells. In our fuel cells, conventionally porous Pt was used as a catalyst layer. In order to reduce the Pt amount, instead of porous Pt, porous Pd was formed on a Si chip and Pt was deposited atomically on the Pd by UPD-SLRR(Under Potential Deposition – Surface Limited Redox Replacement). The PdPt catalyst showed satisfying per...

2017
Thomas H West Daniel M Walden James E Taylor Alexander C Brueckner Ryne C Johnston Paul Ha-Yeon Cheong Guy C Lloyd-Jones Andrew D Smith

A mechanistic study of the isothiourea-catalyzed enantioselective [2,3]-rearrangement of allylic ammonium ylides is described. Reaction kinetic analyses using 19F NMR and density functional theory computations have elucidated a reaction profile and allowed identification of the catalyst resting state and turnover-rate limiting step. A catalytically relevant catalyst-substrate adduct has been ob...

2010
R. P. PRAJAPATI D. R. TIWARI

Spent catalysts are principally solid waste which that coming out from nitrogenous fertilizer industry, during the production of ammonia, resulting in the production of large amount of solid waste containing nickel, which is the spent or deactivated catalysts. These catalysts contain from 12-14% nickel based on the production process in fertilizer industry disposal of spent catalyst is a proble...

2014
Takeshi Matsumoto Masaaki Sadakiyo Mei Lee Ooi Sho Kitano Tomokazu Yamamoto Syo Matsumura Kenichi Kato Tatsuya Takeguchi Miho Yamauchi

An Fe group ternary nanoalloy (NA) catalyst enabled selective electrocatalysis towards CO2-free power generation from highly deliverable ethylene glycol (EG). A solid-solution-type FeCoNi NA catalyst supported on carbon was prepared by a two-step reduction method. High-resolution electron microscopy techniques identified atomic-level mixing of constituent elements in the nanoalloy. We examined ...

2013
Jun Zhang Jibiao Li Shubin Wu Ying Liu

Ni/Cu/Al/Fe hydrotalcite precursor was synthesized by a co-precipitation method. The activity of the reduced precursor for one-step conversion of maltose into sorbitol in the presence of H2 and extremely low phosphoric acid was investigated. XRD and XPS tests provided the essential properties of the precursor and prepared magnetic catalyst. Effects of various processing parameters towards the r...

2015
Frantisek Kastanek Petr Kastanek Anna Kallistova Olga Solcova

Efficiency of reduction of PCBs in aqueous solution was examined with the help of bimetallic catalyst Fe-C/Pd consisting of palladized grey cast iron and with a newly designed trimetallic catalyst (Cu-Fe-C/Pd) consisting of a copper metal plate with embodied microparticles of palladized grey iron (bimetallic catalyst). PCB solutions were prepared using DELOR 103. The trimetallic catalyst was si...

2014
Milton L. Truong Fan Shi Ping He Bingxin Yuan Kyle N. Plunkett Aaron M. Coffey Roman V. Shchepin Danila A. Barskiy Kirill V. Kovtunov Igor V. Koptyug Kevin W. Waddell Boyd M. Goodson Eduard Y. Chekmenev

Activation of a catalyst [IrCl(COD)(IMes)] (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene; COD = cyclooctadiene)] for signal amplification by reversible exchange (SABRE) was monitored by in situ hyperpolarized proton NMR at 9.4 T. During the catalyst-activation process, the COD moiety undergoes hydrogenation that leads to its complete removal from the Ir complex. A transient hydride i...

2010
A. Pasini L. Torre L. Romeo

One of the most critical phenomena that limits the lifetime of ceramic catalysts for H2O2 decomposition is represented by substrate break-up as a consequence of thermal shocking. In a recent experimental campaign conducted by Alta S.p.A., Pisa, Italy, fracture of the ceramic support occurred in a Pt/γ–Al2O3 catalytic bed. Because of the catalyst rupture, the onset of a number of flow instabilit...

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