Pt-based alloy electrode

This is the first experimental demonstration of changes in the strength of CO adsorption at Pt-based alloy electrodes. Nprskov and co-workers theoretically predicted a similar linear relation between changes in ads(CO) and shifts in the (i-band center [Hammer et al., 1996 Hammer and Nprskov, 2000 Ruban et al., 1997]. Because the Pt4/7/2 CL shift due to alloying can be more easily measured by XPS than the li-band center can, this should be one of the most important parameters to aid in discovering CO-tolerant anode catalysts among Pt-based alloys or composites. 

Because of the great potential of methanol as a fuel for low-temperature fuel cells, the electro-oxidation of methanol on Pt or Pt-based alloy electrodes has been studied extensively in the past decades [112-115]. It is generally accepted that methanol is oxidized to CO2 by the so-called dual-path mechanism [112] via adsorbed CO (poison) and non-CO reactive intermediates. The formation of CO by dehydrogenation of methanol has been well confirmed, but no consensus has been reached so far on the nature of the reactive intermediates in the non-CO pathway. Various adsorbates such as CHxOH [116], -COH [116], formyl (-HCO), [117] carboxy (-COOH) [117], a dimer of formic acid [35], and COO [38] have been claimed to be the reactive intermediates from IRAS and other physicochemical measurements. However, the spectra of the reaction intermediates are not well reproduced by other groups. 

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