An environmental friendly dopant for the high-temperature shift catalysts

The high-temperature shift (HTS) reaction is an important step in industria l processes and gas purification. Although the catalyst shows a stable perf ormance, the search for non-toxic systems is much needed, especially due to environmental restrictions related to chromium compounds. In this work, th e performance of aluminum-doped catalysts with low amounts of copper was in vestigated, because of the role of copper on decreasing the surface area of the catalysts based on iron oxides. Samples were prepared by precipitation methods, characterized by several techniques and evaluated under different conditions, in order to find operational conditions more effective in the use of energy. The addition of small amounts of copper to aluminum-doped hematite leads to better catalytic properties. Likely, copper behaves as a structural promot er while aluminum is a textural one. The catalyst can work at more severe c onditions than the industrial condition, that is, lower steam to gas molar ratio (S/G = 0.4) and at a lower temperature (350 degreesC). In addition, i t can be easily handled and discarded without any damage to the environment or human beings. (C) 2000 Published by Elsevier Science B.V.