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High temperature water gas shift catalysts with alumina

Paper ID Volume ID Publish Year Pages File Format Full-Text
42163 45913 2010 9 PDF Available
Title
High temperature water gas shift catalysts with alumina
Abstract

Alumina (Al2O3) was added as a component of conventional iron oxide-based high temperature water gas shift (WGS) catalysts. The catalysts contained Fe–Al–Cr–Cu–O and were synthesized by coprecipitation. A series of catalysts were prepared with 5–50 wt% Al2O3, 8 wt% Cr2O3, 4 wt% CuO, and the balance Fe2O3. One catalyst was prepared in which the chromia was replaced by alumina. All of the catalysts were compared to a reference WGS catalyst (88 wt% FeOx, 8 wt% Cr2O3, and 4 wt% CuO) with no alumina. The catalysts were characterized using temperature programmed reduction (TPR), surface area analysis using nitrogen physisorption, and scanning electron microscopy (SEM) with compositional analysis. The catalysts were also tested kinetically under WGS conditions.Addition of 10–15 wt% alumina increased the catalyst activity and thermal stability, with approximately 15 wt% alumina addition being optimum, as this catalyst produced a reaction rate (normalized per mass) 74% higher than the reference catalyst. The effect of alumina addition was greater than the surface area increase alone, which suggests that alumina alters the activity of the iron oxide domains, likely through an increase in reducibility, as shown by the TPR results. This synergistic effect was only observed when both alumina and chromia were present. Alumina alone (as a replacement for chromia) was not as an effective stabilizer as chromia. Although both the alumina-containing catalyst (without chromia) and the reference with chromia had similar initial surface areas (∼160 m2/g), the alumina-containing catalyst retained only 74% as much surface area after reaction. Results from the catalysts with 50 wt% alumina suggest that the loss of catalytic activity is also due to the formation of aluminates.

Graphical abstractAl2O3 was added as a component of conventional high temperature iron oxide-based water gas shift catalysts. A series of catalysts were prepared with 5–20 wt% Al2O3, each with 8 wt% Cr2O3, 4 wt% CuO, and balance Fe2O3. Addition of 10–15 wt% alumina increased the catalyst activity and thermal stability, with approximately 15 wt% alumina addition being optimum.Figure optionsDownload full-size imageDownload high-quality image (128 K)Download as PowerPoint slide

Keywords
Alumina; Thermal stability; HT water gas shift catalyst
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High temperature water gas shift catalysts with alumina
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 379, Issues 1–2, 15 May 2010, Pages 15–23
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us