Synthesis of borosilicalite-1 with high boron content from fluoride-containing media

Abstract

The synthesis of borosilicalite-1 in fluoride-containing media can lead to a number of boron atoms per unit cell of higher than four, the maximum amount obtained in alkaline media. The preferential countercations to negative charges linked to framework boron [SiOB] − are TPA −, K + and Cs +. It is interpreted that the −3.9 ppm vs. BF 3·OEt 2 NMR line stems from tetrahedral framework boron, while the −2.0 ppm NMR line represents extraframework and/or tetracoordinated deformed framework boron in the structure.