Supported ionic liquid phase (SILP) materials for removal of hazardous gas compounds – efficient and irreversible NH3 adsorption

Abstract

Novel supported ionic liquid phase (SILP) gas purification materials have been developed to remove ammonia irreversibly from an ambient gas flow of nitrogen (1000 ppm NH₃ in N₂, wet and dry). In the applied SILP materials, thin films of imidazolium based ionic liquids and ionic solutions of metal complexes, namely [C₈C₁Im][NTf₂], [C₈C₁Im][NTf₂]/Cu(NTf₂)₂, [C₈C₁Im][NTf₂]/Co(NTf₂)₂ and [C_nC₁Im]Cl/CuCl₂ (n = 2, 4, 8), were dispersed onto the large surface area of polymer-based spherical activated carbon supports. For the [C_nC₁Im]Cl/CuCl₂ (n = 2, 4, 8) based SILP materials the use of a humid gas flow significantly enhances NH₃ absorption as demonstrated by a clear increase of breakthrough times. The irreversibility of the ammonia sorption and the broadband capability (e.g. Cl₂, H₂S and cyclohexane) of the prepared SILP absorber materials are reported and compared to typical standards for gas purification adsorber materials (ABEK regulations).