Control of Morphology and Catalytic Activity of a Cationic Layered Material

Abstract

We have discovered three new synthetic pathways to our two-dimensional cationic inorganic material, antimony oxide hydroxide ethanedisulfonate, [Sb4O4(OH)2](O3SCH2CH2SO3)·H2O. These new methods include room temperature conditions and allow control of crystal size and morphology for improved catalytic performance of the material. As a benchmark reaction, we studied ketalization of 2-butanone with 1,2-ethanediol, a common step for carbonyl group protection. Our material is easily recovered for reuse and gives a higher yield and turnover rates than the typical iodine or toluenesulfonate homogeneous catalyst. The yield ranged between 79 and 92%, with the crystals from reflux conditions giving the highest yield when used as-synthesized. The morphology and properties for each crystal growth method are described in detail. A repeated catalysis study with powdered samples increases the yield to ca. 97%.