Synthesis and characterization of Au nano particles supported catalysts for partial oxidation of ethanol: Influence of solution pH, Au nanoparticle size, support structure and acidity

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Erfan Behravesh, Narendra Kumar, Quentin Balme, Jorma Roine, Jarno Salonen, Andrey Schukarev,
Jyri-Pekka Mikkola, Markus Peurla, Atte Aho, Kari Eränen, Dmitry Yu Murzin, Tapio Salmi
Förläggare: Elsevier
Publiceringsår: 2017
Tidskrift: Journal of Catalysis
Volym: 353
Artikelns första sida, sidnummer: 223
Artikelns sista sida, sidnummer: 238
eISSN: 1090-2694


Abstrakt

Partial oxidation of ethanol to acetaldehyde was carried out over gold
catalysts supported on various oxides and zeolites by deposition
precipitation. The special focus of this work was on the influence of
H-Y zeolite surface charge on Au cluster size and loading linking it to
activity and selectivity in ethanol oxidation and comparing with other
studied catalysts. The catalysts were characterized by nitrogen
physisorption, transmission electron microscopy (TEM), scanning electron
microscopy/energy dispersive X-ray analysis (SEM/EDXA), X-ray
diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier
transform infrared spectroscopy (FTIR) and zeta potential measurements.
pH of the solution governed the Au NPs size within the range of 5.8–13.2 nm
with less negatively charged surfaces leading to formation of smaller
clusters. Au loading on H-Y zeolite with silica to alumina ratio of 80
was increased by raising the pH. In fact, H-Y-12 and H-Beta-25 were
selective towards diethyl ether while acetaldehyde was the prevalent
product on less acidic H-Y-80. The results demonstrated strong
dependency of the catalytic activity on the Au cluster size. Namely turn
over frequency (TOF) decreased with an increase in metal size from 6.3
to 9.3 nm on H-Y-80. Selectivity towards acetaldehyde and ethyl acetate did not change significantly on H-Y-80 within 6.3–9.3 nm Au particle size range. On Al2O3
support, however, selectivity towards acetaldehyde increased
considerably upon diminishing Au average particle size from 3.7 to 2.1 nm.


Nyckelord

Catalyst characterization, Ethanol Oxidation, Heterogenous catalysis, oxides, Zeolites

Senast uppdaterad 2019-19-10 vid 04:33