Co/SiO2 catalysts for selective hydrogenation of crotonaldehyde III. Promoting effect of zinc

Rodrigues, Edson; Bueno, J.M.C.

doi:10.1016/j.apcata.2003.07.002

Cited by 30 publications

(21 citation statements)

References 33 publications

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“…Such charge transfer may also modify the adsorption mode of crontonaldehyde by binding the electron pair of terminal oxygen with the holes in Pt d band. Importantly, depending on the reduction temperatures and preparation procedures the reduced ZnO x species may interact with the supported metal, resulting in modification of electronic density of the metal [23][24][25]. According to our present observation, the zinc chloride or oxychlorinated species in ex-chloride catalysts may have similar interaction with Pt.…”

Section: Discussionmentioning

confidence: 66%

Promotion effect in Pt–ZnO catalysts for selective hydrogenation of crotonaldehyde to crotyl alcohol: A structural investigation

et al. 2009

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Pt-ZnO catalysts prepared from different precursors, H2PtCl6 and Pt(NH3)4(NO3)2, and reduced at increased temperatures are used to achieve high selectivity towards crotyl alcohol in hydrogenation of crotonaldehyde. The ex-chloride catalyst shows a higher activity and selectivity than the ex-nitrate one. Transmission electron microscopy, electron diffraction, high-resolution imaging, energy dispersive X-ray spectroscopy and element mapping are used to characterize the catalysts in order to correlate the microstructure to the catalytic behavior. PtZn alloy formation is confirmed for both ex-chloride and ex-nitrate catalysts reduced at 673 K. The metal particles in ex-nitrate catalyst are smaller in size than those in exchloride. In most aggregates of the ex-chloride catalyst, chlorine is distributed homogeneously with low concentration (<1%). The higher chlorine concentration in some region leads to local morphology and microstructure changes. Influences of the observed structural features such as alloy formation, particle size difference, formation of ill-defined material, and chlorine distribution are discussed.

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Section: Discussionmentioning

confidence: 66%

Promotion effect in Pt–ZnO catalysts for selective hydrogenation of crotonaldehyde to crotyl alcohol: A structural investigation

et al. 2009

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“…Monometallic catalysts containing a metal from group 9 have been used in several chemoselective hydrogenations. Applications of Rh [8,40,[54][55][56][57][58], Co [21,39,59] and Ir [12,21,38,60] were reported. Monometallic catalysts including a metal from group 9 can act quite selectively in some cases, like in citral, acetophenone and cinnamaldehyde hydrogenations.…”

Section: Monometallic Catalystsmentioning

confidence: 98%

Chemoselective hydrogenation of carbonyl compounds over heterogeneous catalysts

Mäki‐Arvela

Hájek

Salmi

et al. 2005

Applied Catalysis A: General

585

478

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“…The first peak of hydrogen consumption in the 510-540 K range was assigned to reduction of the NiO, CoO. A low intensity peak observed at 600 K for the AlNiCo2 sample is characteristic of the reduction of the Co 3 O 4 phase [51,52]. This peak is not clearly observed for the AlNiCo1 sample because of its low intensity and its overlap with the fist peak.…”

Section: Characterizationmentioning

confidence: 98%