The behaviour of Ru/Fe2O3 catalysts and Fe2O3 supports in the TPR and TPO conditions

The texture of Fe2O3 support and Ru/Fe2O3 catalysts supported on iron oxides obtained from beta-FeOOH (B) or delta-FeOOH (D) and their catalytic activity in WGSR were studied. Also their susceptibilities to reduction and reoxidation, were studied by TPR, using H-2 or CO and TPO methods. In the case of TPRCO the composition of the reducing mixture containing traces of H2O enabled investigation of water gas shift reaction (WGSR). The catalysts from series D were found more readily reducible and oxidised than those from series B. The supported ruthenium enhanced the redox effects and caused the appearance of additional effects related directly to its presence. Depending on the kind of support and on ruthenium presence considerable differences in temperatures of WGSR onset were found. It is suggested that the susceptibility of the catalysts to reduction and oxidation is responsible for their activity in the WGSR. (C) 2000 Elsevier Science B.V. All rights reserved.