Hydroformylation pore size

Hydroformylation of pure or technical grade methyl oleate was conducted by Monflier and colleagues [40] under the assistance of activated carbon (Nuchar WV-B mesoporous activated carbon with an average pore size of 3.1 nm) as mass transfer promotor (Scheme 7.9). Noteworthy, in comparison to the hydroformylation with a rhodium-phosphite catalyst in toluene [41], impurities of the technical grade feed did not significantly perturb the reaction. Under similar conditions, also other biomass-based substrates such as methyl hnoleate... 

More recently, studies have been carried out by varying the nature of the supports and the size of the pores [20]. Starting from the catalyst precursor [Rh2(/r-StBu)2(CO)2(TPPTS)2] in the presence of a slight excess of free ligand in order to maintain a molar P/Rh=6 ratio, in such a way that the inactive species [Rh2(/r-StBu)2(CO)4] does not form, the hydroformylation of oct-l-ene has been followed [21]. Sipernat Silica 22 (commercialized by DEGUSSA), characterized by a 100 /rm mean granulometry, a 173 m g BET surface area, and a 45 nm mean pore diameter, has been used as a support. Different hydration rates for this silica, ranging from 1.3 to 47.2 wt % total water content, show that a poor conversion is obtained up to about 12.7%. Beyond this value the yields increase sharply up to 60% when the pores are fully filled with water (16%). 

The influence of the hydration ratio and the physico-chemical properties of five supports in the hydroformylation of 1-octene was also studied [28]. The results confirm that the size of the pores and the amounts of water were found to be the determining factors contributing to SAPC effidency. 

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