Hydrogen adsorption/absorption on Pd/Pt(1 1 1) multilayers

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 621; no. 1; pp. 62 - 68
• Main Authors: Duncan, Hugues, Lasia, Andrzej
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2008; Elsevier Science
• Subjects: Chemistry; Electrochemistry; Electrodes: preparations and properties; Exact sciences and technology; General and physical chemistry; Hydrogen absorption; Hydrogen adsorption; Kinetics; Other electrodes; Pd thin layers; Poison effect; Hydrogen absorption; Pd thin layers; Kinetics; Pt; Poison effect; Hydrogen adsorption; Crystal orientation; Hydrogen; Basic dye; Acidic solution; Sulfuric acid; Electrodes; Cyclic voltammetry; Absorption; Platinum; Inhibition; Platinoid; Modified material; Multilayer; Electrode poisoning; Triarylmethane dye; Transition metal; Palladium; Single crystal; Thickness; Perchloric acid; Adsorption; Medium effect; Methylrosanilinium chloride; Electrochemical impedance spectroscopy
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2008.04.019

One to 20 monolayers of Pd were deposited on Pt(1 1 1) and their electrochemical behavior was studied by cyclic voltammetry and impedance spectroscopy. The hydrogen adsorption and absorption is more reversible at deposits on Pt(1 1 1) as compared to Au(1 1 1), probably due to less strain and/or electronic effects. The quantity of hydrogen adsorbed/absorbed at 10 ML are however comparable at both supports. The charge transfer resistance is lower at 1 Pd ML in perchloric and sulfuric acids than for thicker layers, and it is lower at Pd/Pt(1 1 1) than at Pd/Au(1 1 1). The adsorption pseudocapacitance reaches a maximum at 0.214 V in sulfuric acid for 1 ML and there are two peaks at 0.214 V and 0.255 V for thicker layers. Crystal violet increases the reversibility of hydrogen absorption and inhibits hydrogen adsorption although some residual adsorption remains.