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This study focuses on elucidating the bond breaking steps involved in the electron beam induced deposition (EBID) of nanostructures created from the organometallic precursor cobalt tricarbonyl nitrosyl (Co-(CO) 3 NO) by studying the effect of 500 eV incident electrons on nanometer scale films of Co(CO) 3 NO. Experiments were performed under ultrahigh vacuum conditions, using a suite of surface analytical techniques, principally X-ray photoelectron spectroscopy and mass spectrometry. The purely electron stimulated reactions of Co(CO) 3 NO adsorbed on gold or amorphous carbon substrates at low temperatures (−168 °C) occurs in two distinct steps. The first step involves a one electron process that initiates decomposition of the nitrosyl (NO) ligand to form a nitride, accompanied by the simultaneous desorption of at least one CO ligand to create a partially decarbonylated intermediate. This first step decomposes Co(CO) 3 NO into a nonvolatile Co-containing compound and therefore initiates the EBID process. In the second step, the residual CO ligands in the partially decarbonylated fragments undergo electron stimulated decomposition as opposed to desorption, leading to the formation of adsorbed carbon and oxidized cobalt atoms. However, carbon atoms in the partially decarbonylated species formed during the first step are thermally labile below room temperature. This provides a rationale for the observation that EBID nanostructures created from Co(CO) 3 NO under steady state deposition conditions, at ambient temperatures, typically contain very low levels of carbon contamination. Results from this study highlight the importance that both electron and thermally stimulated processes can play in determining the ultimate chemical composition of nanostructures created by EBID.

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Ethanol represents a promising liquid energy source for fuel cells. The development of direct ethanol fuel cells (DEFCs) is however challenged by the lack of efficient electrocatalysts for the complete oxidation of ethanol to CO 2 . Here we report the investigation of ethanol electro-oxidation on monodisperse and homogeneous Pt 3 Sn alloy nanoparticles. Electrochemical studies were conducted comparatively on the Pt 3 Sn nanoparticles supported on carbon (Pt 3 Sn/C), a commercial Pt/C catalyst, as well as KOH-treated Pt 3 Sn/C with the surface tin species removed. Our studies reveal the dual role of Sn in the EOR electrocatalysis on Pt 3 Sn/C: the surface Sn, likely in the form of tin oxides, enhances the oxidation of *CH x intermediate to *CO; the subsurface metallic Sn weakens the binding of *CO and facilitates its oxidative removal. A synergy of these two roles, plus the presence of Pt surface sites capable of cleaving the C−C bond, gives rise to the enhanced complete oxidation of ethanol.

Toward the goal of better understanding the elementary steps involved in the electron beam-induced deposition (EBID) of organometallic precursors, the present study is aimed at understanding the sequence of electronstimulated reactions of surface-bound η 3 -allyl ruthenium tricarbonyl bromide [(η 3 -C 3 H 5 )Ru(CO) 3 Br], an organometallic complex with three different ligands: carbonyl (CO), halide (Br), and η 3 -allyl (η 3 -C 3 H 5 ). X-ray photoelectron spectroscopy and mass spectrometry were used in situ to probe the effects of 500 eV electrons on nanometer scale films of [(η 3 -C 3 H 5 )Ru-(CO) 3 Br]. Initially, electron irradiation decomposes the precursor, reducing the central Ru atom and causing the ejection of CO ligands into the gas phase. Experimental evidence points to the inability of electron irradiation to remove the carbon atoms of the η 3 -allyl (η 3 -C 3 H 5 ) ligand from the resulting EBID deposits. Although the Br atoms are not labile in the initial molecular decomposition step, they are removed from the film after exposure to higher electron doses as a result of a slower, electron-stimulated desorption process. Comparative studies with [(η 3 -C 3 H 5 )Ru(CO) 3 Cl] reveal that the identity of the halogen does not influence the elementary reaction steps involved in the decomposition process. Collectively, results from these studies suggest that sufficiently volatile organometallic precursors with a small number of carbonyl and halide ligands could be used to generate deposits in EBID with significantly higher metal concentrations (and correspondingly lower levels of organic contamination) compared to existing EBID precursors.