Article ID Journal Published Year Pages File Type
42041 Applied Catalysis A: General 2010 6 Pages PDF
Abstract

Supercritical water (above 374.1 °C and 220.6 bar) is emerging as a promising medium to carry out a variety of catalytic reactions, including reforming to produce hydrogen. However, when using a heterogeneous catalyst the support material can undergo transformations in the hydrothermal environment. In this work the stability of γ-Al2O3 modified with 1–10 wt% Ce in supercritical water is examined, specifically in the temperature range of 500–700 °C at 246 bar. Transformations of the γ-phase were slowed but not prevented. Based on X-ray analysis, the transformation of γ-Al2O3 proceeded through the κ phase toward the stable α phase. Reduced cerium species were seen to be oxidized in the supercritical water environment, and low Ce-loading supports maintained the highest BET surface areas. The stabilization was greatest at 700 °C, where Ce-modified aluminas retained significantly higher specific surface areas than unmodified alumina.

Graphical abstractSupercritical water is emerging as a promising medium to carry out a variety of catalytic reactions. However the support material can undergo transformation in the hydrothermal environment, as shown in the figure below. In this work the stability of a common support material γ-Al2O3 is examined at 500–700 °C and 246 bar.Figure optionsDownload full-size imageDownload high-quality image (171 K)Download as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemical Engineering Catalysis
Authors
, ,