Ham, Hyung Chul Manogaran, Dhivya Hwang, Gyeong S. Han, Jonghee Kim, Hyoung-Juhn Nam, Suk Woo Lim, Tae Hoon 2024-01-20T07:31:48Z 2024-01-20T07:31:48Z 2021-09-05 2015-03-30 0169-4332 https://pubs.kist.re.kr/handle/201004/125640 Using spin-polarized density functional calculations, we investigate the role of different Pd/Pt ensembles in determining CO chemisorption on Au-based bimetallic alloys through a study of the energetics, charge transfer, geometric and electronic structures of CO on various Pd/Pt ensembles (monomer/dimer/trimer/tetramer). We find that the effect of Pd ensembles on the reduction of CO chemisorption energy is much larger than the Pt ensemble case. In particular, small-sized Pd ensembles like monomer show a substantial reduction of CO chemisorption energy compared to the pure Pd (1 1 1) surface, while there are no significant size and shape effects of Pt ensembles on CO chemisorption energy. This is related to two factors: (1) the steeper potential energy surface (PES) of CO in Pd (1 1 1) than in Pt (1 1 1), indicating that the effect of switch of binding site preference on CO chemisorption energy is much larger in Pd ensembles than in Pt ensembles, and (2) down-shift of d-band in Pd ensembles/up-shift of d-band in Pt ensembles as compared to the corresponding pure Pd (1 1 1)/Pt (1 1 1) surfaces, suggesting more reduced activity of Pd ensembles toward CO adsorption than the Pt ensemble case. We also present the different bonding mechanism of CO on Pd/Pt ensembles by the analysis of orbital resolved density of state. (C) 2015 Elsevier B.V. All rights reserved. English ELSEVIER ADSORPTION REACTIVITY PT(111) HYDROGENATION TRANSITION OXYGEN GOLD H2O2 H-2 Role of different Pd/Pt ensembles in determining CO chemisorption on Au-based bimetallic alloys: A first-principles study Article 10.1016/j.apsusc.2015.01.182 1 APPLIED SURFACE SCIENCE, v.332, pp.409 - 418 APPLIED SURFACE SCIENCE 332 409 418 scie scopus 000350373300054 2-s2.0-84924182656 Chemistry, Physical Materials Science, Coatings & Films Physics, Applied Physics, Condensed Matter Chemistry Materials Science Physics Article ADSORPTION REACTIVITY PT(111) HYDROGENATION TRANSITION OXYGEN GOLD H2O2 H-2 Ensembles CO adsorption First-principles AuPd AuPt