Characterization of Surface Structure and Oxidation/Reduction Behaviour of Pd-Pt/Al2O3 Model Catalysts
Artikel i vetenskaplig tidskrift, 2016
Structural and morphological characterisation of bimetallic Pd-Pt/Al2O3 model cat- alysts are performed using X-ray diffraction, X-ray absorption spectroscopy, transmis- sion electron microscopy and CO chemisorption. Further, the catalysts were studied under oxidising and reducing conditions using both X-ray absorption spectroscopy and low-energy ion scattering spectroscopy. For the as-prepared catalysts, the existence of alloyed bimetallic Pd-Pt particles and of (tetragonal) PdO were found for the samples calcined at 800 C. PdO is present in form of crystals at the surface of the Pd-Pt par- ticles or as isolated PdO crystals on the support oxide. Bimetallic Pd-Pt nanoparticles were only formed on the Pd-Pt catalysts after calcination at 800 C. The results show that the Pd-Pt nanoparticles undergo reversible changes in surface structure composi- tion and chemical state in response to oxidising or reducing conditions. Under oxidising conditions Pd segregates to the shell and oxidises forming PdO, while under reducing conditions regions with metallic Pd and Pd-Pt alloys were observed at the surface. No bimetallic Pd-Pt nanoparticles were observed for the sample initially calcined at 500 C, but instead isolated monometallic particles, where small Pt particles are easily oxidised under O2 treatment. In the monometallic catalysts, the Pd is found to be com- pletely oxidised already after calcination and to consist of metallic Pd after reductive treatment.
Författare
Natalia Mihaela Martin
Kompetenscentrum katalys
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Johan Nilsson
Kompetenscentrum katalys
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Magnus Skoglundh
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys
Emma Adams
Kompetenscentrum katalys
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Xueting Wang
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys
Peter Velin
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys
Gudmund Smedler
Agnes Rai
David Thompsett
Hidde Brongersma
Thomas Grehl
Giovanni Agostini
Olivier Mathon
Stefan Carlson
Katarina Norén
Francisco Javier Martinez-Casado
Zdenek Matej
Olivier Balmes
Per-Anders Carlsson
Kompetenscentrum katalys
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Journal of Physical Chemistry C
1932-7447 (ISSN) 1932-7455 (eISSN)
Vol. 120 49 28009-28020Grundläggande studie av vattens inverkan på oxidationskatalysatorer för biogasapplikationer
Energimyndigheten (P40274-1), 2015-04-01 -- 2019-03-31.
Tidsupplösta in situ metoder för design av katalytiska säten för hållbar kemi
Vetenskapsrådet (VR) (2013-567), 2013-01-01 -- 2016-12-31.
Drivkrafter
Hållbar utveckling
Styrkeområden
Nanovetenskap och nanoteknik
Transport
Energi
Materialvetenskap
Ämneskategorier (SSIF 2011)
Fysikalisk kemi
Kemiska processer
Den kondenserade materiens fysik
Infrastruktur
Chalmers materialanalyslaboratorium
DOI
10.1021/acs.jpcc.6b09223