Hydrogenation of crotonaldehyde over ligand-capped Ir catalysts: Metal-organic interface boosts both activity and selectivity

Ir nanoparticles (NPs) were synthesized via a colloidal method using tetradecyltrimethyl ammonium bromide (TTAB) as the ligand, and supported Ir/BN catalysts employed for selective hydrogenation of crotonaldehyde (CRAL). It was found that by proper thermal treatments, TTAB-capped NPs very active reaction. The catalyst calcined at 300 °C with surface TTAB residue gave quasi-steady state turnover frequency (TOF) crotyl alcohol (CROL) formation 0.02 s−1 CROL selectivity 94.4%, while 500 clean TOF 0.004 56.2%. Ir-TTAB interface essential enhanced performance. In-situ IR spectra along kinetic investigation revealed improved CRAL adsorption strengthened C=O adsorption, which accounted high activity selectivity. However, coverage on suppressed H2 consequently lowered activity. Thus findings provided useful information design efficient hydrogenation.