Synergistic effect of Pt or Pd and perovskite oxide for water gas shift reaction

The water gas shift (WGS) reaction over Pt and Pd catalysts supported on various perovskite oxides has been investigated at 573 K without catalyst pretreatment. The Pt and Pd catalysts on LaCoO(3) support showed high catalytic activity. Interaction between Pt or Pd and the support is considered to promote the WGS reaction: Pt/LaCoO(3) had high initial activity but deactivated immediately: Pd/LaCoO(3) was less active than Pt/LaCoO(3), but had superior stability. Catalysts were characterized using XRD, STEM, XPS, and H(2)-temperature programmed reduction (TPR). Results of this study showed that reduction of the support decreased the CO conversion on Pt/LaCoO(3). On the other hand, Pd/LaCoO(3) showed stable activity for the WGS reaction. Therefore, Pd was added to Pt/LaCoO(3) for stabilizing the catalyst activity, and 0.5 wt.% Pd/1 wt.% Pt/LaCoO(3) catalyst showed higher activity and stability. (C) 2008 Elsevier B.V. All rights reserved.