Anion Effects in the UPD of Copper on Pd/Pt(111) Bimetallic Electrodes

摘要: The underpotential deposition (UPD) of copper has been used to characterize the structure palladium films supported on Pt(111). Depending upon nature anions in solution (HSO4-, Cl-, Br-), a variety adsorption behaviors are revealed. In pure sulfuric acid, islands give rise stripping peaks some 100−150 mV negative desorption states associated with As already deduced from hydrogen electrosorption measurements, form at coverages <1 monolayer (mL), and long-range (111) order is preserved within regions surface free palladium, even close completion first monolayer. themselves stable up 0.6 V (Cu2+/Cu), but facilitated 0.8 leaving behind somewhat disordered Pt/Pd phase. contrast, UPD presence strongly adsorbing (Cl-, Br-) leads much narrower range stability [0.3 (Cu2+/Cu)] for ...