Preparation of silica-supported sulfate and its application as a stable and highly active solid acid catalyst

Silica sulfate was prepared by a simple procedure, and proved to be an efficient and recyclable solid acid catalyst. SO3H groups were successfully introduced to silica surface while keeping its structure intact, as proved by XRD patterns and SEM images of the catalyst. With the catalysis of the supported sulfate materials, many of the ketones are efficiently transformed into the corresponding lactones with 30% hydrogen peroxide. In addition, the high performance of silica sulfate as a heterogeneous catalyst was further demonstrated for the esterification of varieties of carboxylic acid with ethanol. (C) 2011 Elsevier B.V. All rights reserved.