Poisoning of Semiconductor Oxides

Because of the presence of electron-donor or electron-acceptor centers with special surface geometries and the fact that redox reactions are favored, general statements about the poisoning of semiconductor catalysts can hardly be made. Any molecule that is strongly adsorbed on the surface is a potential poison. 

Up to now there have been no theoretical models of the poisoning of semiconductor catalysts. They are quite resistant to poisoning, the addition of several per cent of foreign materials being required to give a noticeably lower activity. 

---