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Full-Text Articles in Physics

Electronic And Local Structures Of Pt-Based Bimetallic Alloy And Core-Shell Systems, Jiatang Chen Aug 2020

Electronic And Local Structures Of Pt-Based Bimetallic Alloy And Core-Shell Systems, Jiatang Chen

Electronic Thesis and Dissertation Repository

This thesis investigates the electronic structure of Pt for catalysis applications. The importance of the Pt 5d band is discussed in terms of the bonding capability of Pt. The oxygen reduction reaction in proton exchange membrane fuel cells is chosen as the catalytic reaction model to illustrate the effect of Pt 5d states on Pt-O interaction. Pt-based bimetallic systems are introduced as a solution for the high price and limited resources of Pt. Despite lower usage of Pt, the tuning capability to optimize the Pt 5d band in bimetallic catalysts is supposed to provide superior catalytic activity. Advanced synchrotron X-ray …


Symbiotic Plasmonic Nanomaterials: Synthesis And Properties, Abhinav Malasi May 2016

Symbiotic Plasmonic Nanomaterials: Synthesis And Properties, Abhinav Malasi

Doctoral Dissertations

Metal particles of the dimensions of the order of 1 to 100's of nanometers show unique properties that are not clearly evident in their bulk state. These nanoparticles are highly reactive and sensitive to the changes in the vicinity of the particle surface and hence find applications in the field of sensing of chemical and biological agents, catalysis, energy harvesting, data storage and many more. By synthesizing bimetallic nanoparticles, a single nanoparticle can show multifunctional characteristics. The focus of this thesis is to detail the synthesis and understand the properties of bimetallic nanomaterial systems that show interesting optical, chemical, and …


Atomic And Electronic Structure Of A Ligand-Protected Bimetallic Nanocluster, Ag4ni2(Dmsa)4, Anthony F. Pedicini May 2013

Atomic And Electronic Structure Of A Ligand-Protected Bimetallic Nanocluster, Ag4ni2(Dmsa)4, Anthony F. Pedicini

Theses and Dissertations

An important direction in nanoscale science is to synthesize materials whereby atomic clusters serve as the building blocks. Properties of these clusters can be controlled through size and composition, and such an approach offers a pathway toward designing larger, customized materials. One way to stabilize such materials is through the use of ligated clusters. Ag4Ni2(DMSA)4 is one such cluster, the first with a bimetallic core, and has been stabilized by the experimental group of A. Sen at The Pennsylvania State University. The theoretical studies undertaken in this thesis were directed toward providing information on the atomic structure, nature of electronic …


In-Situ Gas Phase Catalytic Properties Of Metal Nanoparticles, Luis Ono Jan 2009

In-Situ Gas Phase Catalytic Properties Of Metal Nanoparticles, Luis Ono

Electronic Theses and Dissertations

Recent advances in surface science technology have opened new opportunities for atomic scale studies in the field of nanoparticle (NP) catalysis. The 2007 Nobel Prize of Chemistry awarded to Prof. G. Ertl, a pioneer in introducing surface science techniques to the field of heterogeneous catalysis, shows the importance of the field and revealed some of the fundamental processes of how chemical reactions take place at extended surfaces. However, after several decades of intense research, fundamental understanding on the factors that dominate the activity, selectivity, and stability (life-time) of nanoscale catalysts are still not well understood. This dissertation aims to explore …


Core-Level Shifts At The Pt/W(110) Monolayer Bimetallic Interface, D. Mark Riffe, N. D. Shinn, B. Kim, K. J. Kim, T. H. Kang Jan 2009

Core-Level Shifts At The Pt/W(110) Monolayer Bimetallic Interface, D. Mark Riffe, N. D. Shinn, B. Kim, K. J. Kim, T. H. Kang

All Physics Faculty Publications

We have measured W and Pt 4f7/2 core-level photoemission spectra from interfaces formed by ultrathin Pt layers on W(110), completing our core-level measurements of W(110)-based bimetallic interfaces involving the group-10 metals Ni, Pd, and Pt. With increasing Pt coverage the sequence of W spectra can be described using three interfacial core-level peaks with binding-energy (BE) shifts (compared to the bulk) of −0.220 ± 0.015, −0.060 ± 0.015, and +0.110 ± 0.010 eV. We assign these features to 1D, 2D pseudomorphic (ps), and 2D closed-packed (cp) Pt phases, respectively. For ~1 ps ML the Pt 4f7/2 BE is 71.40 ± 0.02 …