CO Oxidation and Site Speciation for Alloyed Pd-Pt Model Catalysts Studied by In Situ FTIR Spectroscopy
Artikel i vetenskaplig tidskrift, 2017

In situ Fourier transform infrared spectroscopy was used to study transient CO oxidation over a series of bimetallic Pd-Pt catalysts with different Pd:Pt molar ratios. The catalysts were found to contain both alloyed PdPt nanoparticles (particle sizes 25-35 nm) and monometallic Pd nanoparticles (sizes below 10 nm). For oxygen-free conditions, CO reduces the surface while simultaneously function as a chemical probe molecule whereby the CO adsorption sites can be characterised. Under these conditions it is shown that adsorbed carbonyl species form both on the Pd and Pt. On platinum, CO adsorbs predominantly linearly on top, whereas on palladium it adsorbes in bridged configurations. This behaviour is used for site speciation of the catalysts. The spectra from the bimetallic Pd-Pt catalysts are more complicated than a direct superposition of the spectra for the monometallic catalysts as a consequence of alloy formation and enrichment of Pd at the surface of the reduced catalysts. The temperature programmed CO oxidation results show that the addition of Pd to the Pt catalyst supported on alumina shifts the CO-poisoned state to lower temperatures therefore increasing the temperature range for the CO oxidation at low temperatures.

Författare

Natalia Mihaela Martin

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Magnus Skoglundh

Kompetenscentrum katalys (KCK)

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Gudmund Smedler

Johnson Matthey AB

Agnes Raj

Johnson Matthey

David Thompsett

Johnson Matthey

Francisco Javier Martinez-Casado

Max IV-laboratoriet

Zdenek Matej

Max IV-laboratoriet

Olivier Balmes

Max IV-laboratoriet

Per-Anders Carlsson

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Teknisk ytkemi

Kompetenscentrum katalys (KCK)

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 121 47 26321-26329

Grundläggande studie av vattens inverkan på oxidationskatalysatorer för biogasapplikationer

Energimyndigheten, 2015-04-01 -- 2019-03-31.

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Transport

Energi

Materialvetenskap

Ämneskategorier

Fysikalisk kemi

Kemiska processer

DOI

10.1021/acs.jpcc.7b07611

Mer information

Senast uppdaterat

2018-10-27