Recovery of Pt Surfaces for Ethylene Hydrogenation-Based Active Site Determination

Abstract

The effect of pretreatment (O2 or H2) and catalyst history was investigated through room temperature ethylene hydrogenation reaction over several types of platinum based nanoparticle systems: 1.6 nm Pt/TTAB, 4.1 nm Pt/PVP (with and without UV treatment), 4.1 nm Pt with a silica shell, and e-beam evaporated Pt thin films were tested. The H2 pretreatment resulted in the absence of activity. However, Pt active sites for the ethylene hydrogenation reaction were recovered after an O2 pretreatment irrespective of the catalyst history, regardless of the particle size nor the presence, absence or type of capping agent. The calculation of the average TOF resulted in 10.13 ± 3.27. This value correlates well with data from the literature. Thus, the ethylene hydrogenation reaction can be used to determine available sites of Pt catalysts if the reaction is following an O2 pretreatment. .