Experimental and modeling study of hydrogenation using deuterium step transient response during ethylene hydroformylation
- Univ. of Akron, OH (United States)
Deuterium isotopic step tracing combined with in situ infrared (IR) spectroscopy was utilized to study and model the hydrogenation steps in ethylene hydroformylation on 4 wt% Rh/SiO{sub 2} at 483-573 K and 0.1 MPa. The difference in residence times between H{sub 2} and D{sub 2}, as well as propionaldehyde and deuterated propionaldehyde to the step switch from H{sub 2} to D{sub 2} and D{sub 2} to H{sub 2} during ethylene hydroformylation reflects the presence of an isotope effect for H{sub 2}/D{sub 2} chemisorption and propionaldehyde formation. Compartment modeling of H{sub 2}/D{sub 2} responses and qualitative comparison of propionaldehyde and deuterated propionaldehyde responses unravel the presence of a normal equilibrium isotope effect for H{sub 2}/D{sub 2} chemisorption and a normal kinetic isotope effect for hydrogenation/deuteration of adsorbed acyl species. In situ IR coupled with deuterium transient responses shows that the reverse spillover of deuterium from Si-OD participates in the deuteration of adsorbed acyl species, suggesting that the site for deuteration of the adsorbed species, suggesting that the site for deuteration of the adsorbed acyl species is located near the Rh and SiO{sub 2} interface. Significant difference in the deuterated ethane and propionaldehyde responses suggests the different nature of either adsorbed hydrogen/deuterium or the active site for hydrogenation/deuteration of adsorbed ethyl and acyl species. 31 refs., 12 figs., 6 tabs.
- OSTI ID:
- 486379
- Journal Information:
- Journal of Catalysis, Vol. 164, Issue 1; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Transient response of propionaldehyde formation during CO/H{sub 2}/C{sub 2}H{sub 4} reaction on Rh/SiO{sub 2}
Kinetics and dynamics of heterogeneous hydroformylation Rh catalyst