A comparative study of copper-promoted water-gas-shift (WGS) catalysts

We studied the catalytic water-gas shift reaction over commercial Cu-ZnO-Al2O3 (LTS-C) and Cu-promoted Fe-Cr oxide (HTS-C) catalysts as well as a high-temperature Cu-promoted (UFR-C) catalyst developed in our laboratory. The catalysts were characterized by different techniques such as X-ray diffraction, thermogravimetry/differential scanning calorimetry, temperature-programmed reduction, and sorption analyses. The activities of these catalysts were evaluated in the compositions of mole fractions having 2.6-16.8% CO, 45% H2O, and the balance nitrogen in the range of 473-973 K. It was observed that the reduction temperature, the ratio of the mass of the catalyst to the mass flow rate of CO (g((cat)) h/mol of CO), and CO concentrations have significant effects on the catalytic activities. In the presence of 2.6% CO, the Cu-ZnO-Al2O3 catalyst was most active at 473 K while the Cu-promoted Fe-Cr oxide catalyst was most active at 773 K. The catalytic activities of HTS-C and LTS-C were compared with that of UFR-C in the presence of both CO in different concentrations and reformate streams as a feed. The results showed that ceria-zirconia-supported non-noble metal catalysts can give very high water-gas shift activity at very short contact times compared to that of the commercial water-gas shift catalyst.