ORCID Profile
0000-0001-6570-0559
Current Organisation
KU Leuven
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Chemical Society (ACS)
Date: 03-03-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TC04674G
Abstract: The applicability of Ag-exchanged zeolites as efficient phosphors for the development of near ultra-violet primary LEDs is described.
Publisher: American Chemical Society (ACS)
Date: 22-11-2005
DOI: 10.1021/JP0556097
Abstract: We report on experiments probing the reactivity of neutral Au(n) clusters, n = 9-68, with carbon monoxide. The gold clusters are produced in a pulsed laser vaporization cluster source, operated at room temperature (RT) or at liquid-nitrogen temperature (LNT), pass through a low-pressure reaction cell containing CO gas, and are subsequently laser ionized. The reaction probabilities are determined by recording mass abundance spectra with time-of-flight mass spectrometry. The main observations are a strong temperature dependence and a remarkable size dependence. Upon cooling of the cluster source to LNT, the reactivity increases substantially. At LNT, the reaction probabilities for Au(n) with the first CO molecule are about a factor 10 higher than at RT. Moreover, adsorption of two, three, and even four CO molecules is observed, in contrast to RT clusters which at most adsorb one CO molecule. This temperature dependence is related to the lifetime of the cluster-molecule complexes, being much longer for cold clusters. The observed striking size dependence is similar at both temperatures and is discussed in terms of the electronic structure effects.
Publisher: American Chemical Society (ACS)
Date: 24-02-2011
DOI: 10.1021/JP111257S
Abstract: Well controlled gas phase experiments of the size and dopant dependent reactivity of gold clusters can shed light on the surprising discovery that nanometer sized gold particles are catalytically active. Most studies that investigate the reactivity of gold clusters in the gas phase focused on charged, small sized clusters. Here, reactivity measurements in a low-pressure reaction cell were performed to investigate carbon monoxide adsorption on neutral bare and silver doped gold clusters (Au(n)Ag(m) n = 10-45 m = 0, 1, 2) at 140 K. The size dependence of the reaction probabilities reflects the role of the electronic shells for the carbon monoxide adsorption, with closed electronic shell systems being the most reactive. In addition, the cluster's reaction probability is reduced upon substitution of gold atoms for silver. Inclusion of a single silver atom causes significant changes in the reactivity only for a few cluster sizes, whereas there is a more general reduction in the reactivity with two silver atoms in the cluster. The experimental observations are qualitatively explained on the basis of a Blyholder model, which includes dopant induced features such as electron transfer from silver to gold, reduced s-d hybrization, and changes in the cluster geometry.
Publisher: American Chemical Society (ACS)
Date: 13-11-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1NR08072E
Abstract: Qualitative different non-linear optical phenomena with high nonlinear cross sections, as measured using the z -scan technique in combination with a tunable nanosecond laser source, were found at different excitation wavelengths.
No related grants have been discovered for Peter Lievens.