Solvent-Free cycloaddition of carbon dioxide and epichlorohydrin catalyzed by surface-attached imidazolium-type poly(ionic liquid) monolayers

•Surface-attached PIL monolayers are synthesized as catalyst for CO2 conversion.•Swelling of PIL layers leads to large numbers of active sites exposed to reactants.•The conversion reaches 90 % under 1.5 MPa CO2 pressure at 120 °C.•The catalyst is easily separated from the products by centrifugation.