Enhancing the catalytic activity of Pt-based alloy by a rational structural design is the key to addressing the sluggish kinetics of direct alcohol fuel cells. Herein, a facile one-pot method is reported to synthesize PtCuRu nanoflowers (NFs). The synergetic effect among Pt, Cu, and Ru can lower the d-band center of Pt, regulate the morphology, generate Ru-rich edge, and allow the exposure of more high index facets. The optimized Pt Cu Ru NFs exhibit outstanding electrocatalytic performances and excellent anti-poisoning abilities. The specific activities for the methanol oxidation reaction (MOR) (7.65 mA cm ) and ethanol oxidation reaction (EOR) (7.90 mA cm ) are 6.0 and 7.1 times higher than commercial Pt/C, respectively. The CO stripping experiment and the chronoamperometric (5000 s) demonstrate the superior anti-poisoning property and durability performance. Density functional theory calculations confirm that high metallization degree leads to the decrease of d-band center, the promotion of oxidation of CO, and improvement of the inherent activity and anti-poisoning ability. A Ru-rich edge exposes abundant high index facets to accelerate the reaction kinetics of rate-determining steps by decreasing the energy barrier for forming *HCOOH (MOR) and CC bond breaking (EOR).
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http://dx.doi.org/10.1002/smll.202204720 | DOI Listing |
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December 2022
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China.
Phys Chem Chem Phys
March 2014
National Synchrotron Radiation Research Center (NSRRC), 101 HsinAnn Road, 30076 Hsinchu, Taiwan.
Mesostructured PtRu nanoparticles were electrochemically reduced from their metallic salts directed by a hexagonally packed microemulsion lyotropic liquid-crystalline (MLLC) template. We investigated the structural evolution and atomic distribution of the MLLC-templated mesoporous PtRu nanoparticles (NPs) after electroreduction for varied duration using X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy, complemented by energy-dispersive X-ray spectroscopy (EDS) and field-emission transmission electron microscopy (FE-TEM). The XANES data at the Ru L2,3 and Pt L3 edges show predominantly metallic states of Ru and Pt in the PtRu NPs upon electroreduction.
View Article and Find Full Text PDFAppl Opt
September 2010
University of Siegen, Walter-Flex Strasse 3, 57068 Siegen, Germany.
Energy dependence of the optical constants of boron carbide in the short period Ru/B(4)C and Mo/B(4)C multilayers (MLs) are evaluated from complete reflectivity scans across the boron K edge using the energy-resolved photon-in-photon-out method. Differences between the refractive indices of the B(4)Cmaterial inside and close to the surface are obtained from the peak profile of the first order ML Bragg peak and the reflection profile near the critical angle of total external reflection close to the surface. Where a Mo/B(4)C ML with narrow barrier layers appears as a homogeneous ML at all energies, a Ru/B(4)C ML exhibits another chemical nature of boron at the surface compared to the bulk.
View Article and Find Full Text PDFJ Phys Chem B
April 2006
Nanoelectrochemistry Laboratory, Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan, Republic of China.
The understanding of the formation mechanism of nanoparticles is essential for the successful particle design and scaling-up process. This paper reports findings of an X-ray absorption spectroscopy (XAS) investigation, comprised of X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) regions, to understand the mechanism of the carbon-supported Pt-Ru nanoparticles (NPs) formation process. We have utilized Watanabe's colloidal reduction method to synthesize Pt-Ru/C NPs.
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