Sorption of oxygen from solution by noble metals: II. Nitric acid-passivated bright platinum

摘要: The nature of the adsorbed films produced on platinum electrodes treated with concentrated nitric acid was studied by means constant current stripping pulses as a function time passivation and contact atmospheric oxygen. It is concluded that dissolved oxygen Pt-O alloy does not come from HNO3. Instead, HNO3 treatment makes Pt more accommodating to sorption (in manner an sponge), then sorbs surroundings producing alloy. presence in lattice modifies electronic structure Pt, generating electrode material different catalytic properties untreated Pt. In oxygen, produces complete monolayer surface. Such exhibits reversible potential O2-saturated, 2 N H2SO4 solution. rest linear degree surface coverage. No than this procedure, but equivalent two layers may be formed anodizing electrode. Apparently sites are converted PtO2 which unstable at potentials below 1500 mV metal. rather stable heating metal vicinity its melting point.