19F/23Na Cross polarization NMR study of hydrofluorocarbon–zeolite binding on zeolite NaY

Abstract

¹⁹ F/²³Na Cross polarization (CP) MAS NMR experiments of various asymmetric hydrofluorocarbons (HFCs) such as CF₃CFH₂ (HFC-134a) and CF₂HCFH₂ (HFC-143) adsorbed on zeolite NaY, demonstrate that the hydrogen-containing groups are bound more strongly to the zeolite framework, in the order CF₃<<CF₂H<CFH₂; the results help explain the preferential binding of CF₂HCF₂H (HFC-134) over HFC-134a, and hence the effectiveness of basic zeolites in the separation of HFC-134/134a gas mixtures.