Introduction
Heterogeneous catalysts play an eminent role in exhaust gas cleaning or the conversion of gases for energy relevant applications such as fuel cells. They are composed of oxide supported metal nanoparticles in random crystallographic orientation, which hampers an “at work” atomic scale investigation. Our aim is to investigate the fundamental properties of supported metal and alloy nanoparticles under gas reaction as well as electrocatalytic conditions. This atomic scale information is a prerequisite for catalysts with tailored reaction activity, reaction product selectivity and improved lifetime.
Current research fields
- Model catalysts under near ambient pressure reaction conditions
- 4d transition metal alloy nanoparticles on single crystal oxide supports
- CO oxidation induced sintering
- Gas adsorption induced nanoparticle shape changes
- High energy x-ray diffraction schemes for in-situ investigations of heterogeneous catalytic reactions
- Adsorption properties of ultra-small metal nanoparticles
- Electrochemical and electrocatalysis in-situ studies
Contact
Dr. Heshmat Noei
Prof. Dr. Andreas Stierle
Project(s) involved
BMBF project CiXENERGY, SFB 1441 TracAct, Helmholtz international graduates school HELIOS
Publications
Identification of a Catalytically Highly Active Surface Phase for CO Oxidation over PtRh Nanoparticles under Operando Reaction ConditionsU. Hejral, D. Franz, S. Volkov, S. Francoual, J. Strempfer, A. Stierle, Phys. Rev. Lettres 120, 2018
Atomic Structure of Pt nanoclusters supported by graphene/Ir(111) and reversible transformation under CO exposure
D. Franz, N. Blanc, J. Coraux, G. Renaud, S. Runte, T. Gerber, C. Busse, T. Michely, P. Feibelman, U. Hejral, A. Stierle, Phys. Rev. B 93, p 4 (2016)
Tracking the shape-dependent sintering of platinum–rhodium model catalysts under operando conditions
U. Hejral, P. Müller, O. Balmes, D. Pontoni, A. Stierle, Nature Communications 7, 10964 (2016)
High-Energy Surface X-Ray Diffraction for Fast Surface Structure Determination, J. Gustafson, M. Shipilin, C. Zhang, A. Stierle, U. Hejral, U. Ruett, O. Gutowski, P.-A. Carlsson, M. Skoglundh, E. Lundgren, Science 343 (6172) 758-61 (2014)
Stability of surface and bulk oxides on Pd(111) revisited by in-situ x-ray diffraction
N. Kasper, P. Nolte, A. Stierle, J. Phys. Chem. C 116 (40), 21459 (2012)
Reversible Shape Changes of Pd Nanoparticles on MgO(100), P. Nolte, A. Stierle, N. Kasper, N. Jeutter, H. Dosch, Nano Lett., 11, 4697 (2011)
Shape Changes of Supported Rh Nanoparticles During Oxidation and Reduction Cycles, P. Nolte, A. Stierle, N. Y. Jin-Phillipp, N. Kasper, T. U. Schulli, H. Dosch, Science 321, 1654 (2008)