fulltext.study @t Gmail

Water-gas shift: Characterization and testing of nanoscale YSZ supported Pt catalysts

Paper ID Volume ID Publish Year Pages File Format Full-Text
39288 45816 2015 14 PDF Available
Title
Water-gas shift: Characterization and testing of nanoscale YSZ supported Pt catalysts
Abstract

•YSZ supports (cubic) are more reducible than zirconia (tetragonal).•Pt promotion further facilitates reduction.•Y-doping of zirconia increases the number of surface defects (e.g., bridging OH groups).•Highest formate decomposition rate (surface O mobility) observed for 0.5%Pt/YSZ.•The activity of Pt/YSZ catalysts displays a synergy between zirconia and yttrium.

Nano-scale Y-doped zirconium oxide materials were prepared with high surface areas (150–200 m2/g) and small nano-crystallites (<8 nm). A combination of XANES and EXAFS was used to show that ZrO2 exhibited the tetragonal phase, while the Zr0.5Y0.5O1.75 support displayed the cubic phase. A comparison with undoped zirconia suggests that the Zr0.9Y0.1O1.95 support was tetragonal in structure. A slight increase in d-spacing observed in HR-TEM for the Zr0.9Y0.1O1.95 support relative to undoped ZrO2, along with a shift to lower 2θ in XRD, provide evidence that Y-doping caused macrostrain. STEM imaging confirmed that the Pt clusters ranged from 0.5 to 2 nm over all three supports.Catalyst reducibility was explored by H2-TPR, XANES at the Zr K-edge, and TPR–XANES at the Pt LIII edge. A higher concentration of surface defects for the 0.5%Pt/Zr0.9Y0.1O1.95 catalyst relative to 0.5%Pt/ZrO2 was confirmed by DRIFTS of adsorbed CO, while a greater surface mobility of surface formate was suggested based on forward formate decomposition experiments in steam. The Y-doped Pt promoted catalysts displayed higher water-gas-shift activity relative to the 0.5%Pt/ZrO2 catalyst when the Y content was at or below 50%, with the best catalyst being 0.5%Pt/Zr0.9Y0.1O1.95.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (78 K)Download as PowerPoint slide

Keywords
Water-gas-shift; Zirconia; Pt/ZrO2; Yttrium stabilized zirconia (YSZ); Pt/YSZ; Surface defects; Surface mobility
First Page Preview
Water-gas shift: Characterization and testing of nanoscale YSZ supported Pt catalysts
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 497, May 2015, Pages 184–197
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