Isotopic transient infrared study of reaction pathway and intermediates for CO insertion and hydrogenation

Abstract A combined in situ infrared with transient D 2 tracing study of ethylene hydroformylation showed that d 1 -propionaldehyde is produced from two modes of acyl hydrogenation: via adsorbed hydrogen on the metal surface and spillover hydrogen from Si-OH. Si-OH was removed by SiH 4 treatment, but was regenerated by CO/H 2 /C 2 H 4 flow. NO pulses into CO/H 2 /C 2 H 4 flow oxidized Rh sites to Rh + sites and decreased catalyst activity.