fulltext.study @t Gmail

Pd catalysts for total oxidation of methane: Support effects

Paper ID Volume ID Publish Year Pages File Format Full-Text
39301 45817 2015 9 PDF Available
Title
Pd catalysts for total oxidation of methane: Support effects
Abstract

•Oxidation activity of Pd catalysts increases with increasing density of surface Pd*–PdO site pairs.•The rate constant's pre-exponent provides a relative measure of site pair density.•Site pair density—and activity—is low when the support stabilizes PdO.

We prepared a series of Pd catalysts for total oxidation of methane on different supports: Al2O3, ZrO2–CeO2 and CeO2. We characterized the catalysts’ structures by XRD and their surface chemistries by temperature programmed reduction (TPR) and oxidation (TPO); and measured their activities for methane oxidation in temperature programmed reaction experiments (TPRx). By fitting a kinetic model to the TPRx results, we extracted apparent activation barriers (Eapp) and pre-exponents (Aapp) for methane oxidation over each of the catalysts. Activity correlates strongly with Aapp, which we interpret as a relative measure of the density of PdO–Pd* (* is an O-vacancy) site pairs. TPR results support this view: PdO in low activity (low Aapp) catalysts, such as Pd/CeO2, is relatively resistant to reduction, meaning that formation of the Pd* partner of the site pair is difficult—and the number of site pairs that can form is low.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (58 K)Download as PowerPoint slide

Keywords
Supported Pd catalysts; Total methane oxidation; Temperature programmed reaction; Temperature programmed reduction
First Page Preview
Pd catalysts for total oxidation of methane: Support effects
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 495, 5 April 2015, Pages 54–62
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