International Journal of Hydrogen Energy, Vol.33, No.2, 762-774, 2008
Determination of adsorption isotherms of hydrogen and hydroxide at Pt-Ir alloy electrode interfaces using the phase-shift method and correlation constants
At the Pt-Ir (Pt:Ir; 70:30 wt%) alloy/0.5M H2SO4 aqueous solution interface, the Frumkin and Temkin adsorption isotherms (theta(H) vs. E), equilibrium constants (K-H = 3.1 x 10(-5) exp(2.5 theta(H))mol(-1) for the Frumkin and K-H = 3.1 x 10(-4) exp(-2.1 theta(H))mol(-1) for the Temkin adsorption isotherm), interaction parameters (g = -2.5 for the Frumkin and g = 2.1 for the Temkin adsorption isotherm), rates of change of the standard free energy of H with OH (r = -6.2 kJ mol(-1) for g = -2.5 and r = 5.2 kJ mol(-1) for g = 2.1), and standard free energies (25.7 >=Delta G(0)(0)>= 19.5 kJ mol(-1) for K-H = 3.1 x 10(-5)exp(2.5 theta(H))mol(-1) and 0 <=theta(H)<= 1 and 21.1< Delta G(0)(0)<24.2kJ mol(-1) for K-H=3.1 x 10(-4)exp(-2.1 theta(H))mol(-1) and 0.2
Keywords:phase-shift method;correlation constants;adsorption isotherms;hydrogen and hydroxide adsorptions;Pt-Ir alloy electrode