Disclosed are novel catalyst systems comprising (1) a diorgano fluorophosphite
ligand; (2) rhodium, wherein the ratio of gram moles fluorophosphite ligand (1)
to gram atoms of rhodium is at least 1:1; and (3) a Group VIII metal, other than
rhodium, or Group VIII metal-containing compound, in an amount effective to reduce
the formation of HF during the use of the catalyst system. The presence of the
other Group VIII metal decreases the amount of hydrogen fluoride produced during
the use of the catalyst system. The hydrogen fluoride originates from very low
level degradation of the ligand. Also disclosed are novel catalyst solutions of
the aforesaid catalyst system and the use of the catalyst system in the hydroformylation
of olefins to produce aldehydes.
