TY - JOUR

T1 - On the importance of the structure in the catalytic reactivity of Au-based catalysts

AU - Jacobs, Luc

AU - von Boehn, Bernhard

AU - Homann, Mathias

AU - Barroo, Cédric

AU - Visart de Bocarmé, Thierry

AU - Imbihl, Ronald

N1 - Funding Information: L.J. and C.B. thank the Fonds de la Recherche Scientifique (F.R.S.-FNRS) for financial support: PhD grant from FRIA (L.J.) and postdoctoral fellowship from FNRS (C.B.). L.J. also thanks the Wallonie-Bruxelles International (Excellence grant WBI.WORLD) for financial support. B. v. B. thanks the Department of Inorganic Chemistry of the Fritz Haber Institute of the Max Planck Society for financial support.

PY - 2020/9/30

Y1 - 2020/9/30

N2 - Au-based materials are remarkably efficient catalysts in the domain of partial oxidation reactions. Nonetheless, questions remain about the physico-chemical phenomena involved at the molecular level. In this work, the catalytic properties of Au-Ag samples, in the form of ultrathin Ag layers on a Au(1 1 1) surface and Au-based model nanoparticles, have been investigated with different microscopy techniques. Using photoemission electron microscopy (PEEM), the exposure of a Au(1 1 1) single crystal doped with various amounts of Ag (0 to 3 monolayers) to O2/H2 and O2/CH3OH gas mixtures did not lead to any specific spatiotemporal pattern formation. In contrast, the use of curved nanoscopic Au and Au-8.8 at.% Ag tip-samples analysed by field emission microscopy (FEM) under similar experimental conditions indicates the presence of catalytic activity. The influence of the silver concentration and of the morphology on the reactivity is discussed. This work highlights the necessity of different experimental approaches aimed at bridging the materials gap often encountered between surface science studies and applied catalysis.

AB - Au-based materials are remarkably efficient catalysts in the domain of partial oxidation reactions. Nonetheless, questions remain about the physico-chemical phenomena involved at the molecular level. In this work, the catalytic properties of Au-Ag samples, in the form of ultrathin Ag layers on a Au(1 1 1) surface and Au-based model nanoparticles, have been investigated with different microscopy techniques. Using photoemission electron microscopy (PEEM), the exposure of a Au(1 1 1) single crystal doped with various amounts of Ag (0 to 3 monolayers) to O2/H2 and O2/CH3OH gas mixtures did not lead to any specific spatiotemporal pattern formation. In contrast, the use of curved nanoscopic Au and Au-8.8 at.% Ag tip-samples analysed by field emission microscopy (FEM) under similar experimental conditions indicates the presence of catalytic activity. The influence of the silver concentration and of the morphology on the reactivity is discussed. This work highlights the necessity of different experimental approaches aimed at bridging the materials gap often encountered between surface science studies and applied catalysis.

KW - Au-Ag

KW - Field emission microscopy

KW - Gold catalysis

KW - In situ microscopy

KW - Photoemission electron microscopy

UR - http://www.scopus.com/inward/record.url?scp=85084422644&partnerID=8YFLogxK

U2 - 10.1016/j.apsusc.2020.146568

DO - 10.1016/j.apsusc.2020.146568

M3 - Article

AN - SCOPUS:85084422644

VL - 525

JO - Applied surface science

JF - Applied surface science

SN - 0169-4332

M1 - 146568

ER -