Manufacture of opal-matrix functional nanocomposites by catalytic dehydrogenation of isopropanol under supercritical conditions

Abstract

The products of redox reactions that occur during the manufacture of opal matrix nanocompos ites in isopropanol under supercritical conditions are studied. Experimental data, thermodynamic calcula tions, and reaction yield values imply that hydrogen is formed in the catalytic dehydrogenation of isopropanol to acetone under supercritical conditions. The alcohol dehydrogenation catalysts are ultrafine d element oxides encapsulated in the pore space of an ordered opal matrix; in a closed experimental system (an auto clave), these oxides are reduced by hydrogen to metals or to lower oxides (or the oxygen stoichiometry of higher oxides changes).