Ammonia oxidation over a Pt25Rh75(001) model catalyst surface: an operando study

DOI: 10.1021/acs.jpcc.0c07128

Authors: Andrea Resta (Synchrotron SOLEIL) , Uta Hejral (Lund University) , Sara Blomberg (Lund University) , Stefano Albertin (Lund University) , Alina Vlad (Synchrotron SOLEIL) , Yves Garreau (Universite de Paris) , Corentin Chatelier (Synchrotron SOLEIL; Universite de Lorraine, CNRS) , Federica Venturini (Diamond Light Source) , Pilar Ferrer (Diamond Light Source) , Georg Held (Diamond Light Source) , Dave Grinter (Diamond Light Source) , Edvin Lundgren (Lund University) , Alessandro Coati (Synchrotron SOLEIL)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: The Journal Of Physical Chemistry C

State: Published (Approved)
Published: September 2020
Diamond Proposal Number(s): 21936

Abstract: The reaction of ammonia oxidation over PtRh binary alloy has been studied with a surface science approach by operando techniques such as Near Ambient Pressure X-Ray Photoemission Spectroscopy (NAP-XPS) and Surface X-Ray Diffraction (SXRD) combined with mass spectrometry. The article will explore the surface evolution across five different oxygen to ammonia ratios in the millibar regime for two different temperatures. The presented data-set allows to link variations in the atomic structures measured by diffraction methods and surface species information from NAP-XPS to reaction products in the gas phase. We will show that NO production coincides with significant changes of the surface structure and the formation of a RhO2 surface oxide. It was also observed that the RhO2 surface oxide only fully forms when the nitrogen signal in the N1s has disappeared.

Subject Areas: Chemistry


Instruments: B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS