Self organization of composite model catalysts : vanadium and nickel oxides on Rh(111) Inverted model catalyst rhodium vanadium oxide nickel oxide PEEM LEEM self organization stationary patterns reactive phase separation spinodal decomposition chemical wave patterns rate oscillations. Inverser Modellkatalysator Vanadiumoxid Nickeloxid Selbstorganisation stationäre Muster reaktive Phasentrennung spinoidale Entmischung chemische Wellenmuster Ratenoszillationen