Controlling Ethylene Hydrogenation Reactivity on Pt₁₃ Clusters by Varying the Stoichiometry of the Amorphous Silica Support

Abstract

Ethylene hydrogenation was investigated on size-selected Pt13 clusters supported on three amorphous silica (a-SiO2 ) thin films with different stoichiometries. Activity measurements of the reaction at 300 K revealed that on a silicon-rich and a stoichiometric film, Pt13 exhibits a similar activity to that of Pt(111), in line with the known structure insensitivity of the reaction. On an oxygen-rich film, a threefold increased rate was measured. Pulsing ethylene at 400 K, then measuring the activity at 300 K, resulted in complete loss of activity on the silicon-rich surface compared to only marginal losses on the other surfaces. The measured reactivity trends correlate with charging characteristics of a Pt13 cluster on the SiO2 films, predicted through first-principle calculations. The results reveal that the stoichiometry-dependent charging by the support can be used to tune the selectivity of reaction pathways during a catalytic hydrogenation reaction.

Metal Catalysts for Heterogeneous Catalysis: From Single Atoms to Nanoclusters and Nanoparticles

“…When Pt 13 clusters were supported on oxygen-deficient SiO 2 film, they showed activity similar to Pt(111) surface. However, when the support was changed to oxygen-rich SiO 2 film, a 3-fold increase of activity could be observed for hydrogenation of ethylene …”

The interaction of ethylene with free gold cluster cations: infrared photodissociation spectroscopy combined with electronic and vibrational structure calculations

“…Notably, none of these experimental and theoretical studies on gold surfaces and clusters indicate the decomposition of ethylene to e.g. ethylidyne as has for example been reported to occur on platinum extended surfaces [38,39] and supported Pt clusters [24,40,41].…”

Spectroscopy for model heterogeneous asymmetric catalysis

“…Our understanding of heterogeneous catalysis in general (not only for asymmetric catalysis) is still lagging behind compared with homogeneous catalysis. However, the latest studies on model heterogeneous catalysts under controlled conditions have been gaining enormous momentum [48][49][50][51][52] and have led to speeding advances in the field even under more realistic conditions. [53][54][55][56] This progress has only been possible as a result of the collaboration between theoretical researchers and experimentalists.…”