Some physical and chemical properties of sprayed silver alloy catalysts

Abstract

AbstractSpraying of silver alloy catalysts by powder flame spray and by molten alloy spray techniques is briefly described. Some of the physical properties such as density, porosity, thermal conductivity and diffusibility are listed for catalysts prepared from 8.5% calcium in silver alloy, as well as a few data on pure silver, copper and nickel. Initial rate data from the oxidation of ethylene have been compiled to show a diffusion effect within the catalyst layer, and these data have been used to calculate a diffusibility factor which is lower than a similar factor estimated from oxygen‐helium diffusion experiments. The kinetic data were obtained from catalyst strips immersed in an inert mullite powder bed fluidized with reacting air‐ethylene mixture. Heat transfer coefficients from strip to bed were estimated from the kinetic data, exothermic heats of reaction and recorded temperature differences.