Rhodium catalyst for NBR hydrogenation and its recovery method

Rhodium metal catalyst was used in the field of NBR homogeneous hydrogenation. A new extraction method of noble metal rhodium catalyst recovery from hydrogenated NBR (HNBR) solution has been researched. Rhodium metal catalyst can be efficiently removed from HNBR solution using SnCl ₂ as ligand and HCl as extractant. The condition of removing rhodium catalysts from HNBR solution has been studied, including reaction temperature, reaction time, SnCl ₂ concentration and proportion of aqueous phase to organic phase, and the removal of the rhodium metal catalyst is over 99% under the best conditions. IR and ¹H NMR characterization show that HNBR structure and nitrile group have no change after rhodium metal catalyst is removed from HNBR solution.