In situ time-resolved X-ray diffraction studies of Fe_2O_3 and Cu,Cr-Fe_2O_3 catalysts for the water-gas shift reaction

摘要

The activation process and performance of Fe_2O_3 and an industrial Cu,Cr-Fe_2O_3 catalyst for the water-gas shift reaction were analysed by in situ time-resolved X-ray diffraction. We show that the catalytic activity in the case of Fe_2O_3 is related to the Fe_2O_3 --> Fe_2O_3 transformation. However, in the case of the industrial Cu,Cr-Fe_2O_3 catalyst, the presence of Cu has a major effect, and strongly increases the catalytic activity, even before the full transformation to Fe_2O_3 takes place. The smaller Fe_2O_3 crystalline domains, detected by diffraction, should also contribute to make the industrial Cu,Cr-Fe_2O_3 the most active catalyst.