Ham, Hyung Chul Hwang, Gyeong S. Han, Jonghee Yoon, Sung Pil Nam, Suk Woo Lim, Tae Hoon 2024-01-20T04:31:54Z 2024-01-20T04:31:54Z 2021-09-05 2016-04-01 0920-5861 https://pubs.kist.re.kr/handle/201004/124185 Based on density functional theory calculations, we present that pairs of 1st nearest Pd monomers play an important role in significantly enhancing the oxygen reduction reaction (ORR) on the AuPd(100) surface. While the catalytic ORR activity tends to be sensitive to the surface atomic ordering, we find that the Pd monomer pairs lead to a substantial reduction in the activation barrier for O/OH hydrogenation with no significant suppression of O-O bond scission, thereby considerably lowering the overall activation energy for the ORR as compared to the case of pure Pd(100). On the other hand, an isolated Pd monomer tends to greatly suppress the O-O bond cleavage reaction, which in turn slows down the ORR kinetics. Unlike the monodentate adsorption of O-2 on an isolated Pd monomer, the pairing of Pd monomers allows O-2 adsorption in a bidentate configuration and consequently facilitating O-O bond scission. However, the barrier for OH hydrogenation at each Pd site shows no significant change between the isolated and paired cases, while it is noticeably lower than the pure Pd case. (C) 2015 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE BV DENSITY-FUNCTIONAL THEORY HYDROGEN-PEROXIDE ATOMIC ARRANGEMENTS ADSORPTION ENSEMBLES ALLOYS H-2 CHEMISORPTION CLUSTERS PD(111) Importance of Pd monomer pairs in enhancing the oxygen reduction reaction activity of the AuPd(100) surface: A first principles study Article 10.1016/j.cattod.2015.07.054 1 CATALYSIS TODAY, v.263, pp.11 - 15 CATALYSIS TODAY 263 11 15 scie scopus 000368587700003 2-s2.0-84955450911 Chemistry, Applied Chemistry, Physical Engineering, Chemical Chemistry Engineering Article DENSITY-FUNCTIONAL THEORY HYDROGEN-PEROXIDE ATOMIC ARRANGEMENTS ADSORPTION ENSEMBLES ALLOYS H-2 CHEMISORPTION CLUSTERS PD(111) AuPd(100) Ensembles ORR First-principles