Heterogeneous Cu-Fe oxide catalysts for preferential CO oxidation (PROX) in H-rich process streams.

The influence of Fe loading in Cu-Fe phases and its effect on carbon monoxide (CO) oxidation in H-rich reactant streams were investigated with the catalyst material phases characterized by Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD) studies and Mössbauer Spectroscopy (MS). There was no change in the oxidation state of the Fe ions with copper or iron loading. The catalytic activity was examined in the feed consisting of H, HO and CO for the preferential CO oxidation (PROX) process. These catalysts showed an optimized performance in converting CO in WGS streams in the temperature range of 80-200 °C. In addition to the formation of the CuFeO phase, the Fe and Cu were found to be incorporated into a Cu-Fe supersaturated solid solution which improved CO oxidation activity, with carbon dioxide and water produced selectively with high catalytic activity in depleted hydrogen streams. Relatively high conversion of CO was obtained with high Fe metal loading. In addition to their catalytic efficiency, the employed heterogeneous catalysts are inexpensive to produce and do not contain any critical raw materials such as platinum group metals.