Recently, the use of ionic liquids as alternativesto organic solvents has attracted much attention of either scientific or industrial researchers. Their potential to reduce pollution in industrial processes has led to investigation of ionic liquids as alternative reaction media for a variety of applications that conventionally use organic solvents. A novel approach to immobilizing homogeneous catalysts on solid supports (supported ionic liquid phase – SILP catalyst) has been reported, in which the hydroformylation complex catalyst was distributed in ionic liquid medium contained in pore system of a solid support.