EFFECT OF PH ON RATE AND SELECTIVITY BEHAVIOR IN BIPHASIC HYDROFORMYLATION OF 1-OCTENE

The effect of pH on activity and selectivity of (RhCl(COD)(2)/TPPTS ca talyzed hydroformylation of 1-octene in a biphasic medium has been stu died. The pH of the aqueous catalyst phase shows a strong influence on the rate of reaction and n/iso ratio of the aldehyde products. The ef fect of P/Rh ratio, catalyst and 1-octene concentration, partial press ure of hydrogen and carbon monoxide was studied at 7 and 10 pH, which showed significantly different trends. The rates increased by two- to five fold when the pH was changed from 7 to 10, While the dependence o f the rate was found to be linear on the olefin and hydrogen concentra tion at both 7 and 10 pH, the rate of hydroformylation was found to be inhibited with increase in catalyst concentration beyond 1 X 10(-3) k mol m(-3). The effect of partial pressure of carbon monoxide was linea r at pH 7 whereas at pH 10 a substrate inhibited kinetics was observed . (C) 1997 Elsevier Science B.V.