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Surface Acid–Base Properties of Anion-Adsorbed Species at Pt(111) Electrode Surfaces in Contact with CO 2 -Containing Perchloric Acid Solutions

2016; American Chemical Society; Volume: 120; Issue: 29 Linguagem: Inglês

10.1021/acs.jpcc.6b00589

1932-7455

Ricardo Martínez‐Hincapié, Antonio Berná, Antonio Rodes, Vı́ctor Climent, Juan M. Feliú,

CO2 Reduction Techniques and Catalysts

Carbonate and bicarbonate adsorption on Pt(111) electrodes from CO2-saturated acidic solutions is investigated by cyclic voltammetry and Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS). Spectroscopic results show carbonate and bicarbonate adsorption even at pH = 1, where bulk concentration of these anions is negligible. Moreover, analysis of the potential dependence of band intensities corresponding to adsorbed carbonate and bicarbonate reveals an effect of the electrode potential on the surface acid–base equilibrium. In this regard, increasing potentials favor bicarbonate deprotonation, leading to carbonate formation. A tentative thermodynamic analysis is given to rationalize these trends.