Monolithic SiC supports with tailored hierarchical porosity for molecularly selective membranes and supported liquid-phase catalysis

Gas‐Phase Hydroformylation Using Supported Ionic Liquid Phase (SILP) Catalysts – Influence of Support Texture on Effective Kinetics

“…An excellent n/iso ‐selectivity of above 96 % n ‐pentanal in all experiments was achieved using the Rh‐bpp system. Similar values for the isomerization selectivity of 38 % using either [P 14666 ][NTf 2 ] or [C 2 C 1 im][NTf 2 ] were obtained, matching literature known data for the Rh‐bpp complex [31,49,50] The hydrogenation selectivity, leading to butane, was stable for all tested size fractions at 6 % using [P 14666 ][NTf 2 ] and 7 % using [C 2 C 1 im][NTf 2 ].…”

Porous Silicon Carbide (SiC): A Chance for Improving Catalysts or Just Another Active-Phase Carrier?

“…Notably, their MW-synthesized Pd/SiC catalyst showed improved stability and long-term reusability in Heck cross-coupling with only moderate activity loss even after 20 successive catalytic tests. 162 Multichanneled, hierarchically structured monolithic SiC matrices with properly tailored macro-and mesoporous voids were selected as supports for the liquid-phase immobilization of a molecular Rh-bpp catalyst [BiPhePhos; 6,6′-[(3,3′-di-tertbutyl-5,5′-dimethoxy-1,1′-biphenyl-2,2′-diyl)bis(oxy)]bis- 164 The supported liquid-phase (SLP) composite was then used as a macroscopically shaped reactor for the model 1-butene hydroformylation reaction. These solid reactors hold all classical advantages of heterogeneous catalysts that authors elegantly combined with those of a homogeneous single-site catalyst (especially the specific activity and selectivity).…”

Tailored monolith supports for improved ultra-low temperature water-gas shift reaction

“…Afterwards, an outer support layer consisting of sub-micrometer sized α-SiC particles was applied to create a homogeneous surface, and finally the structure was washcoated with 7 nm SiO 2 particles to provide an improved interface with the catalyst. [18] 1.3.2 New mesoporous supports Pure -alumina mesoporous monoliths with the geometry required for this work were obtained by mechanical extrusion and subsequent calcination at 550 ºC using boehmite as alumina precursor, water as peptizing agent, and additives, as described elsewhere. [25] Additionally, alumina-rich extrudates were prepared with different proportions of bentonite, for new composition screening, as these provide very good mechanical stability, mesoporosity, and plasticity, respectively.…”

“…Given the highly hygroscopic nature of [C 4 C 1 C 1 Im]Cl, significant amounts of water dissolved in the ionic liquid, leading to swelling. Strong capillary forces inside small mesopores might prevent the removal of this aqueous ionic liquid film from the pores, but the large macropores of the SiC monolith [18] could not fulfill this task of proper ionic liquid film fixation. As a result, the chloride-containing ionic liquid-metal-complex-solution leached from the monolith and corroded the reactor material and its downstream section (e.g.…”

“…The incorporation of the thin ionic liquid film into the monolithic structure is highly beneficial [15] , as intrinsic kinetics, fluid dynamics, and transport phenomena can be optimized independently in such structured reactors, [16] and modeling, scale-up, and process control are simplified. Very recently, some of us have successfully applied this approach for but-1-ene hydroformylation, [17] showing stable and efficient operation over 40 h time on stream (TOS) using the same SiO 2 -washcoated SiC monoliths [18] as support to immobilize Rhdiphosphite complexes. [19] A high pressure-drop was avoided by the macroporosity as well as the channeled design of the structure, and the SiC provided heat conductivity, mechanical strength, and chemical inertness.…”