부산대학교 도서관

The use of functional CO 2 -philic polymers in supercritical carbon dioxide (scCO 2 ) for a greener method of extracting Pd from spent catalysts has been investigated. Three fluorinated polymers bearing complexing units (a thiol-terminated poly(1,1,2,2-tetrahydroperfluorodecyl acrylate) homopolymer PFDA-SH, a poly(1,1,2,2-tetrahydroperfluorodecyl acrylate- co -diphenylphosphinostyrene) gradient copolymer P(FDA- co -DPPS), and a thiol-terminated gradient copolymer P(FDA- co -DPPS)-SH) were synthesized and successfully used to extract palladium from commercial Pd/Al 2 O 3 supported catalysts (beads and pellets with 0.5 wt.% and 5 wt.% Pd loading, respectively). These non-destructive extractions were carried out in scCO 2 under mild conditions (40 °C and 25 MPa). Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis on the Pd/Al 2 O 3 catalysts before and after extraction confirmed the removal of palladium from the catalytic supports. Up to 40% of palladium was extracted from the commercial supported catalysts with full recovery of the original alumina support. [ABSTRACT FROM AUTHOR]