title: Relating the composition of Pt(x)Ru(100-x)/C nanoparticles to their structural aspects and electrocatalytic activities in the methanol oxidation reaction.
abstract: A controlled composition-based method--that is, the microwave-assisted ethylene glycol (MEG) method--was successfully developed to prepare bimetallic Pt(x)Ru(100-x)/C nanoparticles (NPs) with different alloy compositions. This study highlights the impact of the variation in alloy composition of Pt(x)Ru(100-x)/C NPs on their alloying extent (structure) and subsequently their catalytic activity towards the methanol oxidation reaction (MOR). The alloying extent of these Pt(x)Ru(100-x)/C NPs has a strong influence on their Pt d-band vacancy and Pt electroactive surface area (Pt ECSA); this relationship was systematically evaluated by using X-ray absorption (XAS), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), density functional theory (DFT) calculations, and electrochemical analyses. The MOR activity depends on two effects that act in cooperation, namely, the number of active Pt sites and their activity. Here the number of active Pt sites is associated with the Pt ECSA value, whereas the Pt-site activity is associated with the alloying extent and Pt d-band vacancy (electronic) effects. Among the Pt(x)Ru(100-x)/C NPs with various Pt:Ru atomic ratios (x = 25, 50, and 75), the Pt(75)Ru(25)/C NPs were shown to be superior in MOR activity on account of their favorable alloying extent, Pt d-band vacancy, and Pt ECSA. This short study brings new insight into probing the synergistic effect on the surface reactivity of the Pt(x)Ru(100-x)/C NPs, and possibly other bimetallic Pt-based alloy NPs.
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, #43, Sec. 4, Keelung Rd., Taipei, 10607, Taiwan, ROC.
authors.forename: Fadlilatul
authors.initials: F
authors.lastname: Taufany
authors.forename: Chun-Jern
authors.initials: CJ
authors.lastname: Pan
authors.forename: Feng-Ju
authors.initials: FJ
authors.lastname: Lai
authors.forename: Hung-Lung
authors.initials: HL
authors.lastname: Chou
authors.forename: Loka Subramanyam
authors.initials: LS
authors.lastname: Sarma
authors.forename: John
authors.initials: J
authors.lastname: Rick
authors.forename: Jhih-Min
authors.initials: JM
authors.lastname: Lin
authors.forename: Jyh-Fu
authors.initials: JF
authors.lastname: Lee
authors.forename: Mau-Tsu
authors.initials: MT
authors.lastname: Tang
authors.forename: Bing-Joe
authors.initials: BJ
authors.lastname: Hwang
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D055664:Electrochemical Techniques; D000432:Methanol / Q000737:chemistry*; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D011789:Quantum Theory; D012428:Ruthenium / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D010984:Platinum; D002244:Carbon; D012428:Ruthenium; D000432:Methanol