Octahedral palladium nanoparticles as excellent hosts for electrochemically adsorbed and absorbed hydrogen.
We report new results for electrochemical H adsorption on and absorption in octahedral palladium nanoparticles (Pd-NPs) with an average tip-to-tip size of 7.8 nm and a narrow size distribution. They reveal a very high H loading of 0.90 that cannot be achieved using bulk Pd materials or larger NPs; this behavior is assigned to a combination of two factors: their small size and face morphology. Temperature-dependent cyclic voltammetry (CV) studies in the range of 296 to 333 K reveal unique features that are attributed to electrochemical H adsorption, H absorption, and H2generation. The CV features are used to prepare H adsorption and absorption isotherms that are then used in thermodynamic data analysis. Modeling of the experimental results demonstrates that, upon H adsorption and absorption, Pd-NPs develop a core-shell-skin structure, each with its unique H loading. The electrochemical results obtained for octahedral Pd-NPs are compared to analogous data obtained for cubic Pd-NPs with a similar size as well as for larger cubic Pd-NPs and bulk materials under gas-phase conditions.
Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), UMR CNRS 7285, Equipe "Catalyse et Milieux Non Conventionnels," Université de Poitiers, 4 rue Michel Brunet, TSA 51106, 86073 Poitiers Cedex 9, France.
Anna
A
Zalineeva
Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), UMR CNRS 7285, Equipe "Catalyse et Milieux Non Conventionnels," Université de Poitiers, 4 rue Michel Brunet, TSA 51106, 86073 Poitiers Cedex 9, France.
Stève
S
Baranton
Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), UMR CNRS 7285, Equipe "Catalyse et Milieux Non Conventionnels," Université de Poitiers, 4 rue Michel Brunet, TSA 51106, 86073 Poitiers Cedex 9, France.
Christophe
C
Coutanceau
Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada.
Gregory
G
Jerkiewicz
electrochemistry hydrogen adsorption; hydrogen absorption; nanoparticles; palladium; thermodynamics