cs5b02747_si_001.pdf (211.42 kB)
Boosting the Activity in Supported Ionic Liquid-Phase-Catalyzed Hydroformylation via Surface Functionalization of the Carbon Support
journal contribution
posted on 2016-02-16, 00:00 authored by Alexander Weiß, Macarena Munoz, Alexander Haas, Florian Rietzler, Hans-Peter Steinrück, Marco Haumann, Peter Wasserscheid, Bastian J. M. EtzoldSupported ionic liquid phase (SILP)
catalysts are comprised of
a thin ionic liquid film containing a homogeneous transition metal
complex that is supported on a highly porous substrate. The application
of functionalized activated carbon as a support material for SILP
catalysts in a continuous gas-phase propene hydroformylation reaction
reveals that the surface properties of the carbon support have a significant
influence on the catalytic performance. The catalytic activity of
the pristine activated carbon-based SILP catalysts was found to be
negligibly small (TOF4h = 3.5 h–1) in
contrast to that of common oxidic supports such as silica (TOF4h = 15 h–1) or alumina. By amine functionalization
of the carbon support surface, a dramatic increase in catalytic activity
could be observed outperforming the tested oxidic supports by an order
of magnitude. A distinct relationship between increased nitrogen content
and the point of zero charge of the support and the catalytic activity
could be observed. The largest activity increase (TOF4h = 105 h–1) was found for functionalized activated
carbon SILP catalysts featuring a high point of zero charge and a
high nitrogen content. Despite the fact that aldol formation is catalyzed
by a base, the respective alcohol was the only detectable byproduct
in the reactions.