In this dissertation, nano-manufacturing of amorphous alloys for electro-catalytic applications is reported and the role of chemistry and active surface area on catalytic behavior is discussed. The catalytic activity of recently developed platinum and palladium-based metallic glasses was studied using cyclic voltammetry and localized electrochemical techniques. The synergistic effect between platinum and palladium was shown for amorphous alloys containing both these elements. The mechanism for superior catalytic behavior was investigated through electronic structure and surface chemical state of the alloys. A correlation between the work function and catalytic performance of the amorphous alloys with widely varying chemistries was established. To address the high cost associated with the noble-metal containing catalysts, the performance of non-noble Ni-P amorphous catalyst was evaluated for electro-catalysis. A facile pulsed electrodeposition approach was used for the nano-manufacturing of these amorphous catalysts. This nano-manufacturing route allowed the synthesis of fully amorphous nano-wires at room temperature for alloys with little or no noble-metal content. A wide range of nano-wires with varying aspect ratios from 25 to 120 was synthesized using commercially obtained anodic aluminum oxide (AAO) nano-molds. Cyclic voltammetry and chrono-amperometry demonstrated superior performance in terms of electrocatalytic activity and stability of the metallic glass nano-wires towards electro-oxidation of methanol. The mechanism for amorphization during pulsed electrodeposition is discussed and compared with the conventional approach of rapid quenching of the liquid melt.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc1609096 |
| Date | 12 1900 |
| Creators | Hasannaeimi, Vahid |
| Contributors | Mukherjee, Sundeep, Xia, Zhenhai, Mishra, Rajiv, Aouadi, Samir, Nasrazadani, Seifollah |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | xii, 133 pages, Text |
| Rights | Use restricted to UNT Community, Hasannaeimi, Vahid, Copyright, Copyright is held by the author, unless otherwise noted. All rights Reserved. |
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