High-water-resistance catalytic paper produced by ionic liquid-treatment for use under aqueous conditions

In the present study, we prepared a heterogeneous catalytic paper with high water resistance for reactions under aqueous conditions. A cellulose paper containing the catalyst calcium vanadate apatite (VAP) and with high water resistance was prepared by treatment with 1-butyl-3-methyl-imidazolium chloride ([BMIM]Cl). We subsequently determined the dry and wet strengths of this cellulose paper and its ability to catalyze the Knoevenagel condensation. The wet tensile strength of cellulose paper containing VAP and treated with [BMIM]Cl was higher than that of cellulose paper not treated with [BMIM]Cl. During a batch Knoevenagel condensation, cellulose paper containing VAP and treated with [BMIM]Cl exhibited high catalytic function and effectively produced ethyl α-cyanocinnamate from benzaldehyde and ethyl cyanoacetate. The [BMIM]Cl on the paper prevented loss of the VAP catalyst. The cellulose paper was easily recovered from the solution after the catalytic reaction. This paper is promising for use as a solid catalyst for heterogeneous reactions.