Active phase of iron catalyst for alcohol formation in hydrogenation of carbon oxides

Hydrogenation of CO2 over iron catalysts has been carried out and compared with the activity obtained,vith CO. The rates of hydrocarbon and alcohol fo rmation were higher in the reaction with CO. The rates of hydrocarbon and a lcohol formation were suppressed by addition of steam to the reactant gas m ixture of H-2-COx. Although no significant change in the structure of the c atalyst was observed by the X-ray diffraction analyses, change in the oxida tion state of the surface iron was detected by recording X-ray photoelectro n spectroscopy of the catalysts. During the reaction with CO, the catalyst surface was further reduced even after the reduction at 500 degreesC, where as it was oxidized in the reaction with CO2, A change in product distributi on and the results of X-ray photoelectron spectroscopy analyses showed that the iron carbide is the active site for hydrocarbon formation and the oxyg en species in iron hydroxide (O-Fe-OH) may be relevant to the formation of MeOH, Copyright (C) 2000 John Wiley & Sons, Ltd.