An in situ infrared spectroscopic investigation of the role of ethylidyne in the ethylene hydrogenation reaction on palladium/alumina

Bonding and chemistry of hydrocarbon monolayers on metal surfaces

“…Analogous results for a Pt(111) catalyst have been published [61]. It was found that these monolayers of ethylidyne were quite stable under one atmosphere of hydrogen or deuterium [6,63]. As shown in Figure How, then, do these ethylidyne-covered surfaces catalyze the hydrogenation of gas phase ethylene?…”

Direct Observation of Surface Ethyl to Ethane Interconversion upon C2H4 Hydrogenation over Pt/Al2O3 Catalyst by Time-Resolved FT-IR Spectroscopy

“…17 On the other hand, the ethylidyne surface species (CH 3 CPt 3 ) familiar from early HREELS and reflection-absorption infrared surface work 8,9,18,19 was determined to play no kinetically significant role in the catalytic hydrogenation. 9,20,21 These experimental findings on Pt or Pd surfaces are supported by recent DFT computational work. [22][23][24][25] The papers predict that the barrier to hydrogenation is substantially lower for π-C 2 H 4 than for di-σ ethylene (at the high surface coverage relevant for reaction conditions), and that the barrier for ethyl to ethane conversion exceeds that of step (1) by a factor between 2 and 5.…”

Catalysis with Supported Size-selected Pt Clusters

“…For the ethylidyne species the question arises as to whether it is a simple spectator [112] or does it have a more active role in the hydrogenation of ethene [62]. The current opinion is [113], that it does not actively participate in the reaction, however blocks the sites available for ethene adsorption [63] or react with hydrogen and thus indirectly affects the reaction kinetics of hydrogenation [111,114].…”