Electrosorption impedance on Pt(111)in sulphuric media and nature of the “unusual” state

International audienceImpedance measurements, up to 1 MHz, not only in sulphuric acid but also with supporting electrolytes for H+ or for anions, confirmed that the usual peaks on Pt(111) are related to a fast hydrogen electrosorption, and that the “unusual” state is due to sulphate anion electrosorption on the whole pH range, or to hydrogenosulphate at low pH and to sulphate above pH 2