We have addressed the problem of determining a reliable experimental descriptor of surface chemical reactivity by measuring Pd and Ru 3d(5/2) core-level shifts of the Pd(n)/Ru(0001) pseudomorphic overlayer system (n = 0-3) by high resolution X-ray photoelectron spectroscopy. We find a linear relationship between the calculated theoretical changes of the d-band center position projected on each Ru and Pd atomic layer (which is, according to the Hammer and Norskov d-band model, a good theoretical descriptor of chemical reactivity) and the corresponding core-level shifts, both for the Ru atomic planes and for the Pd overlayers. Core-level shifts, therefore, should be considered as reliable experimental descriptors of chemical reactivity in the same sense (and with similar limitations) of the theoretical descriptor d-band center. Final-state effect contributions to the shifts do not obscure this trend.
Determining the Chemical Reactivity Trends of Pd/Ru(0001) Pseudomorphic Overlayers: Core-Level Shift Measurements and DFT Calculations / Golfetto, E; Baraldi, A; Pozzo, M; Alfe, D; Sala, A; Lacovig, P; Vesselli, E; Lizzit, S; Comelli, G; Rosei, R. - In: JOURNAL OF PHYSICAL CHEMISTRY. C. - ISSN 1932-7447. - 114:1(2010), pp. 436-441. [10.1021/jp908568v]
Determining the Chemical Reactivity Trends of Pd/Ru(0001) Pseudomorphic Overlayers: Core-Level Shift Measurements and DFT Calculations
Alfe D;
2010
Abstract
We have addressed the problem of determining a reliable experimental descriptor of surface chemical reactivity by measuring Pd and Ru 3d(5/2) core-level shifts of the Pd(n)/Ru(0001) pseudomorphic overlayer system (n = 0-3) by high resolution X-ray photoelectron spectroscopy. We find a linear relationship between the calculated theoretical changes of the d-band center position projected on each Ru and Pd atomic layer (which is, according to the Hammer and Norskov d-band model, a good theoretical descriptor of chemical reactivity) and the corresponding core-level shifts, both for the Ru atomic planes and for the Pd overlayers. Core-level shifts, therefore, should be considered as reliable experimental descriptors of chemical reactivity in the same sense (and with similar limitations) of the theoretical descriptor d-band center. Final-state effect contributions to the shifts do not obscure this trend.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
