Deuterium Pulse Transient Analysis for Determination of Heterogeneous Ethylene Hydroformylation Mechanistic Parameters

Synthesis of Heteroatom Rh–ReOx Atomically Dispersed Species on Al2O3 and Their Tunable Catalytic Reactivity in Ethylene Hydroformylation

“…The similar ethylene dependence and slightly smaller H 2 dependence in the rate laws for propanal formation and ethane formation are consistent with the experimentally observed reaction orders. Acyl hydrogenation has also been identified as a kinetically relevant step in propanal formation, which may account for the greater than 0.5 order (∼0.7) observed for H 2 dependence . The CO reaction orders decreased by about twofold for propanal formation as compared to ethane formation, which is again consistent with the rate laws.…”

Recent Approaches in Mechanistic and Kinetic Studies of Catalytic Reactions Using SSITKA Technique

“…Deuterium isotopic pulse tracing into a steady-state CO/H 2 /C 2 H 4 flow has been also useful in combination with in situ spectroscopic techniques to study the hydroformylation and hydrogenation of ethylene over a Mn− Rh/SiO 2 catalyst at 513 K and 0.1 MPa. 33 The steady-state rate of hydrogen desorption coupled with compartment models allowed the calculation of the complete assortment of kinetic parameters. Hydrogen desorption was estimated by the HD transient assuming that the H and D coverages are similar when the production rates of HD, D 2 , and H 2 are the same.…”

Mechanism of C2+ oxygenate synthesis on Rh catalysts

“…Deuterium tracing studies revealed that hydrogenation of adsorbed ethyl species involves hydrogen adsorption onto the metal surface [78]; hydrogenation of adsorbed acyl employs hydrogen from Si-OH that migrates from the metal surface to the SiO 2 support surface (i.e., spillover) [78,79]. Figure 9 highlights the experimental approach and results of a study that distinguishes the different types of adsorbed hydrogen involved in the hydrogenation of adsorbed ethyl and acyl species [78].…”

“…Figure 9 highlights the experimental approach and results of a study that distinguishes the different types of adsorbed hydrogen involved in the hydrogenation of adsorbed ethyl and acyl species [78]. The first step is to expose the Rh/SiO 2 catalyst to D 2 (i.e., deuterium) followed by isolating deuterium on the SiO 2 surface (Si-OD) by reacting away the hydrogen adsorbed on the Rh surface with ethylene.…”

“…Incorporation of Si-OD in d 1 -propionaldehyde formation at 513 K: (a) product and Si-OD profiles and (b) transient Si-OD infrared spectra (reprinted from[78] with permission form Elsevier).…”