Chemistry of supported palladium nanoparticles during methane oxidation
Journal article, 2015

Time-resolved in situ energy-dispersive X-ray absorption spectroscopy and mass spectrometry are used to correlate changes in chemical state of alumina and ceria supported palladium nanoparticles with changes in activity and selectivity for methane oxidation. Specifically, modulation excitation spectroscopy experiments are carried out by periodically cycling between net-reducing and net-oxidizing reaction conditions. The XANES and EXAFS data show that the palladium nanoparticles are readily bulk oxidized when exposed to oxygen, forming a PdO-like phase, and reduced back to a reduced (metal) phase when oxygen is removed from the feed. The difference between the two support materials is most noticeable at the switches between net-oxidizing and net-reducing reaction conditions. Here, a brief reduction in conversion is observed for the alumina supported catalyst, but for the ceria this reduction in conversion is minor or not observed at all. This difference is attributed to differences in the oxidation kinetics and the oxygen storage capability of ceria.

XAFS

methane

in situ

modulation excitation

homogeneous catalysis

Author

Johan Nilsson

Competence Centre for Catalysis (KCK)

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Per-Anders Carlsson

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

Sheedeh Fouladvand

Competence Centre for Catalysis (KCK)

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Natalia Mihaela Martin

Competence Centre for Catalysis (KCK)

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Johan Gustafsson

Lund University

Mark Newton

European Synchrotron Radiation Facility (ESRF)

Edvin Lundgren

Lund University

Henrik Grönbeck

Competence Centre for Catalysis (KCK)

Chalmers, Applied Physics, Chemical Physics

Magnus Skoglundh

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Competence Centre for Catalysis (KCK)

ACS Catalysis

2155-5435 (eISSN)

Vol. 5 4 2481-2489

Time-resolved in situ methods for design of catalytic sites within sustainable chemistry

Swedish Research Council (VR), 2013-01-01 -- 2016-12-31.

Unravelling catalytically active sites with X-ray absorption spectroscopy

Swedish Research Council (VR), 2012-01-01 -- 2015-12-31.

Driving Forces

Sustainable development

Areas of Advance

Nanoscience and Nanotechnology

Transport

Energy

Materials Science

Subject Categories

Physical Chemistry

Chemical Process Engineering

Atom and Molecular Physics and Optics

Roots

Basic sciences

DOI

10.1021/cs502036d

More information

Latest update

10/27/2018