| Abstract: | The pre-use state of industrial α-Fe2O3/Cr2O3 CO-conversion catalysts of known activity has been investigated by means of MÖSSBAUER effect and BET measurements. The iron of various catalyst samples has been found at room and catalytic reaction temperature (330°C) to be as well in the antiferro- as in the paramagnetic state, the ratio of both states being strongly dependent on temperature and on the specific catalyst sample. As the main reason for the occurrence of these two states within each sample the simultaneous occurrence of differently sized powder particles may be supposed. The ratio difference between one and another sample is due to differing chemical composition and grain size. Since no correlation was found between these resulats, BET surface data, grain size distribution and/or catalytic activity, pore structure differences are assumend to explain the observed differences in sample activity. |
