e-journal

Tuning the support adsorption properties of Pd/SiO2 by silylation to improve the selective hydrogenation of aromatic ketones

---

Abstract.
Silylation of Pd/SiO2 catalysts increases the selectivity toward alcohols in the reduction of aromatic
ketones. This work demonstrates that the selectivity is directly related to the adsorption strength of the
alcohol on the surface of the support relative to the adsorption strength of the ketone. This observation
can be explained by interaction of the support coverage with the metal coverage. Silylation yields a
more hydrophobic support, on which the aromatic alcohol adsorbs more weakly relative to the ketone, in
turn decreasing the amount of the alcohol adsorbed on the metal and thus suppressing the consecutive
reduction of the alcohol. Silylation was carried out by using di-alkyl (dichlorodimethylsilane) and trialkyl
(hexamethyldisilazane and hexamethyldisilane) silylating agents. Hexamethyldisilazane provided to
be the most effective agent in terms of incorporation of methyl groups, catalyst hydrophobicity, and
stability. Selective hydrogenation of 4-isobutyl acetophenone (4-IBAP) to 4-isobutylphenyl ethanol (4-
IBPE) revealed that not only was the fresh hexamethyldisilazane-silylated Pd/SiO2 catalyst more selective
than the untreated catalyst, but also the silylated catalyst was much more selective after a deactivation–
regeneration cycle than the untreated Pd/SiO2 catalyst. The change in selectivity can be explained by a
change in the relative adsorption strength of 4-IBPE over 4-IBAP on silylation.

Keywords:
Pd catalyst
Silylation
Physisorption
Selective hydrogenation
Hydrophobicity

---

Ketersediaan

Tidak ada salinan data

Informasi Detail

Judul Seri

Journal of Catalysis

No. Panggil

-

Penerbit

London : Elsevier Inc.., 2008

Deskripsi Fisik

Journal of Catalysis 257 (2008) 55–63

Bahasa

English

ISBN/ISSN

00219517

Klasifikasi

-

Tipe Isi

-

Tipe Media

-

Tipe Pembawa

-

Edisi

-

Subjek

KIMIA

Info Detail Spesifik

-

Pernyataan Tanggungjawab

agus

Versi lain/terkait

Lampiran Berkas

Komentar

---

Anda harus masuk sebelum memberikan komentar