Accession Number : AD1051354


Title :   Young Investigator Proposal, Research Area 7.4 Reactive Chemical Systems: Multifunctional, Bimetallic Nanomaterials Prepared by Atomic Layer Electroless Deposition


Descriptive Note : Technical Report,01 Oct 2016,30 Jun 2017


Corporate Author : University of Massachusetts - North Dartmouth North Dartmouth United States


Personal Author(s) : Cappillino,Patrick J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/1051354.pdf


Report Date : 30 Sep 2017


Pagination or Media Count : 16


Abstract : For many applications of bimetallic materials an atomically thin adlayer of the alloying metal is desirable. In these cases, a surface adlayer metal tunes the energy of the d-band at the catalyst interface. In other cases, islands of adlayer atoms are desirable, for example to resist catalyst poisoning, or as so-called single atoms catalysts, leaving some fraction of underlying substrate exposed. A potential feature of Atomic Layer Electroless Deposition (ALED, Figure 1) is the ability to tune growth mechanism, hence growth morphology, by altering conditions. In this funded effort, we set out to probe this possibility by controlling the addition rate of adlayer metal during deposition cycles (galvanic displacement of Pt-H surface hydrides with Pd2+ ions) and measuring changes in surface morphology. Based on a LaMer mechanism of particle growth, we hypothesized that high concentrations of Pd2+ resulting from fast addition would exceed a critical nucleation concentration, leading to a more uniform adlayer, while slow addition would favor particle growth leading to islands of adlayer metal.


Descriptors :   transmission electron microscopy , chemical reactions , nanomaterials , decomposition , electrons , hydrogen , catalysts , METAL ALLOYS , oxidation


Subject Categories : Properties of Metals and Alloys


Distribution Statement : APPROVED FOR PUBLIC RELEASE