Extraction of copper in ZSM-5 with a RTIL

Abstract

Speciation of copper extracted with a RTIL (room temperature ionic liquid) ([C4mim][PF6], l-butyl-3-methylimida-zolium hexafluorophosphate) has been studied by extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectroscopy in the present work. The extraction of copper in the chan-nels of ZSM-5 with the RTIL turns out to be very effective. The least-square fitted XANES spectra show that the main copper species (Cu2+(adS) (99%)) in the channels of ZSM-5 can be extracted with the RTIL and form the Cu(mim) 42+ complex. The bond distance of Cu-N in the Cu(mim) 42+ is 1.96 Å with a coordination number of 3.6.