fulltext.study @t Gmail

Role of alkali metal in a highly active Pd/alkali/Fe2O3 catalyst for water gas shift reaction

Paper ID Volume ID Publish Year Pages File Format Full-Text
40423 45853 2013 11 PDF Available
Title
Role of alkali metal in a highly active Pd/alkali/Fe2O3 catalyst for water gas shift reaction
Abstract

•Pd/K/Fe2O3 catalyst shows high activity for water gas shift (WGS) reaction.•The K/Pd molar ratio on the catalyst has a remarkable effect on WGS activity.•The addition of alkali metals (Na, K and Cs) drastically enhanced WGS activity.•WGS on Pd/K/Fe2O3 catalyst proceeded via redox using lattice oxygen.•The synergetic effect of Pd and K brought high redox ability and structural stability.

Pd/K/Fe2O3 catalyst shows high activity for water gas shift (WGS) reaction. The K/Pd molar ratio on the catalyst has a remarkable effect on WGS activity. The optimum K/Pd molar ratio is about 2. In this study, to clarify the role of alkali metal (potassium), WGS activities of Pd/alkali/Fe2O3 (alkali: Li, Na, K or Cs) catalysts were investigated and the reaction mechanism over the Pd/K/Fe2O3 catalyst was examined with transient response analyses using a concentration jump method with a quadrupole mass spectrometer (Q-Mass). Results showed that the addition of alkali metals such as Na, K and Cs drastically enhanced WGS activity, except for Li-loaded catalyst. WGS reaction over the highly active Pd/K/Fe2O3 catalyst was found to proceed via reduction–oxidation (redox) using lattice oxygen. Thereby, CO was oxidized by lattice oxygen in Fe2O3. The consumed lattice oxygen was regenerated by H2O. The results of CO-TPR revealed that oxidation of CO by lattice oxygen were enhanced by K, Cs or Na addition. H2-TPR results showed that reduction of Fe2O3 was suppressed by an increment of loading amount of potassium, which brought a high stability for the WGS reaction. The result of CO/H2O-TPR showed that steam can promote the regeneration of consumed lattice oxygen. The synergistic effect brought a high release ability of lattice oxygen for CO oxidation and also high regenerating ability of consumed lattice oxygen by H2O to produce hydrogen, to the Pd/K/Fe2O3 catalyst. It enabled high catalytic performance of the Pd/K/Fe2O3 catalyst with K/Pd molar ratio of 2.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (123 K)Download as PowerPoint slide

Keywords
Water gas shift; Hydrogen production; Alkali metal addition; Redox; Lattice oxygen
First Page Preview
Role of alkali metal in a highly active Pd/alkali/Fe2O3 catalyst for water gas shift reaction
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
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 457, 24 April 2013, Pages 1–11
Authors
, , , , , ,
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