Reduction of chloroacetone over silica-supported noble metal catalysts

The reduction of chloroacetone over silica-supported noble metal catalysts yielded the hydrodechlorinated (acetone), the hydrogenated (1-chloro-2-propanol), and the hydrodechlorinated-hydrogenated (2-propanol) products at different selectivities depending on the catalyst used. Pd/SiO2 catalyzed the single-step hydrodechlorination preferentially to give acetone selectively. Pt/SiO2 promoted the hydrogenation into 1-chloro-2-propanol concurrently and the consecutive hydrogenation of acetone into 2-propanol as well. Over Rh/SiO2, acetone was transformed to 1-chloro-2-propanol through the addition of hydrogen chloride. The hydrodechlorination activity of noble metals followed the order of Pd > Pt much greater than Rh > Ru. The high selectivity of Pd/SiO2 toward acetone was not influenced by Pd dispersion. The selectivity Of Pt/SiO2 changed largely with Pt dispersion and the hydrogenation of carbonyl group was promoted preferentially over the catalysts with low Pt dispersion. (C) 2004 Elsevier B.V. All rights reserved.