Supported gold catalysts prepared by using nano-sized gold particles dispersed in nylon-11 oligomer

Gold catalysts supported on titanium oxide (TiO2) have been prepared by using nano-sized gold particle/nylon-11 oligomer composites. The composite was prepared through vapor-deposition of gold onto a nylon-11 oligomer film followed by heat treatment. The gold particles/nylon-11 oligomer composite in solution was adsorbed rapidly on the surface of TiO2. When the gold particles/nylon-11 oligomer composite adsorbed on TiO2 was calcined at various temperatures in air, nano-sized gold particles were supported directly on the surface of TiO2 without coagulation. The catalytic activity of the gold particles for oxidation of CO was measured in a flow type reactor. The catalytic activity of gold supported on TiO2 prepared by a one-stage calcination was not so high as that of gold-catalysts reported previously. This result was considered to be due to growth of the size of the gold particles during calcination. When the calcination was carried out in two stages (the first at 500 degrees C in vacuum, and the second at 400 degrees C in air), the growth of the size of the gold particles was suppressed considerably. The supported gold catalyst thus obtained showed very high activity for the oxidation of CO, with a temperature of -10 degrees C for 50% conversion of CO.