Main Factors Influencing the Efficiency of SAPC

Many typical parameters usually investigated in biphasic catalysis, such as temperature, pressure, the excess of water-soluble ligand, and the nature of the reactants and the catalyst, have roughly similar effects on SAPC. 

As seen before, a major difference with respect to biphasic catalysis is the low dependence on substrate solubility in the catalytic aqueous phase as the SAPC reaction occurs at the interface. SAPC is strongly dependent on the water content of the solid support. Two types of water content effects have been reported usually SAPC is efficient over a very restricted hydration range where activity exhibits a clear peak, while only recently a large plateau was observed in a higher hydrahon range. 

1- hexene with aqueous phosphine-Rh complexes supported on non-porous fumed-silica nanoparticles [33]. A positive effect on the reaction performance was observed for the particle size and strrface area of the nanopartides. 

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. 

Most authors have found the excess of water-soluble ligands to have limited effects on both activity and selectivity for linear/branched aldehydes, whether the optimum hydration ratio zone was narrow or wide. The ratio of hnear aldehydes (about 80%) is lower than that observed in biphasic aqueous catalysis. 

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