Partial hydrogenation of methyl esters of sunflower oil catalyzed by highly active rhodium sulfonated triphenylphosphite complexes

The partial hydrogenation of polyunsaturated methyl esters of sunflower oil to monounsaturated methyl esters catalyzed by highly active rhodium sulfonated phosphite (Rh/STPP) complexes was studied in order to improve the quality of biodiesel in terms of increased oxidative stability and higher cetane numbers. The hydrogenation reaction proceeds under mild conditions and high catalytic activities (TOF=38,000h−1) were achieved employing Rh/STPP catalysts at a P/Rh molar ratio of 4 at 30–130 °C, 10–70bar hydrogen partial pressure and molar ratios of CC/Rh between 700 and 6000 within 5–60min of reaction time in conventional organic media.