The Effect of Zn Promoter on Enhanced Diffusion During Catalytic Formation of Methylchlorosilanes

摘要: The copper-catalyzed direct synthesis of methylchlorosilanes was carried out at atmospheric pressure and 550 K on four planar Cu3Si alloy surfaces contained <0.1 at% zinc tin promoters. Kinetics were measured in a batch reactor attached to an ultrahigh vacuum chamber that allowed Auger surface analysis after reaction. Concentration depth profiles obtained by ion sputtering analysis. These measurements showed reaction almost completely depleted silicon the subsurface regions both unpromoted tin-promoted samples. presence promoter low concentrations (0.04-0.06 at%), however, dramatically increased diffusion rates so zinc-promoted samples not silicon. rate is probably due grain. boundary diffusion. A synergistic interaction between further This dramatic increase concentration indicates one important role promoters catalytic methylchlorosilanes.