Sárkány, Antal and Geszti, Olga and Sáfrán, György (2008) Preparation of Pd-shell-Au-core/SiO2 catalyst and catalytic activity for acetylene hydrogenation. APPLIED CATALYSIS A-GENERAL, 350 (2). pp. 157-163. ISSN 0926-860X
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Abstract
Various Pd shell thicknesses (0.12-1.5 nm) were synthesized on preformed Au particles of 5 nm size by seeded growth technique (15-80 at% Pd) using sodium citrate and tannic acid. The sols were characterized by UV-vis spectroscopy, TEM and high-resolution TEM (HRTEM) measurements. HRTEM confirmed the pseudomorphic growth of the Pd shell on the Au core. The Au/Pd core/shell particles were fixed onto SiO2 (Aerosil 200) support by PDDA polycation. The catalytic activity in acetylene hydrogenation and selectivity of competition between acetylene and propene were tested after O-2 and H-2 pretreatment. The samples even in "as prepared" state hydrogenated acetylene. The thin Pd layer (15-30 at% Pd) on Au provided higher hydrogenation activity than the thick Pd shell. However, thermal treatment of the samples in H-2 stream causing Au/Pd intermixing shifted the activity maximum to higher Pd concentration (68-80 at% Pd). Comparison of the TOF (1/s) and selectivity values allowed us to conclude that the homogenized particle with 68-80 at% Pd shows better hydrogenation activity and selectivity than the thin Pd shell (15-30 at% Pd) on the Au core. (C) 2008 Elsevier B.V. All rights reserved.
Item Type: | Article |
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Subjects: | Q Science / természettudomány > QC Physics / fizika |
SWORD Depositor: | MTMT SWORD |
Depositing User: | MTMT SWORD |
Date Deposited: | 14 Feb 2019 10:07 |
Last Modified: | 14 Feb 2019 10:07 |
URI: | http://real.mtak.hu/id/eprint/91293 |
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