Hamish Miller - Academia.edu (original) (raw)
Papers by Hamish Miller
We report an interesting new class of bifunctional electrocatalysts, Pd/C-CeO 2 , with excellent ... more We report an interesting new class of bifunctional electrocatalysts, Pd/C-CeO 2 , with excellent activity and stability for the hydrogen oxidation reaction (HOR) under alkaline conditions. The unique structure of palladium deposited onto a mixed support of Vulcan XC-72 carbon and CeO 2 consists of Pd metal preferable deposited on the ceria regions of the catalyst. The CeO 2-Pd interaction leads to enhanced HOR kinetics and increased stability. Here we compare catalysts with three different Pd loadings and show that the 10 wt% Pd sample has optimized activity. Hydrogen pumping and fuel cell experiments based on this catalyst show higher activities as compared to a Pd/C sample without ceria. Metal dissolution tests and identical location transmission microscopy experiments show that the catalyst stability under harsh potential cycling experiments in alkaline medium is significantly improved as compared to Pd/C, making this material one of the best options for use as highly active and highly stable electrocatalysts for the HOR in anion exchange membrane fuel cells.
Journal of CO2 Utilization, 2014
Journal of Power Sources, 2012
ABSTRACT We synthesized two “single-core” Fe–Nx/C and Cu–Nx/C electrocatalysts and a bi-core CuFe... more ABSTRACT We synthesized two “single-core” Fe–Nx/C and Cu–Nx/C electrocatalysts and a bi-core CuFe–Nx/C composite electrocatalyst using iron and copper phthalocyanine-based precursors and a high-temperature pyrolysis method. The morphology, structure, and activity toward the oxygen reduction reaction (ORR) in alkaline media were evaluated for each electrocatalyst by transmission electron microscopy (TEM), X-ray Diffraction (XRD), and the rotating ring-disk electrode (RRDE) method. Although the Cu–Nx/C catalyst showed lower catalytic activity than Fe–Nx/C, the presence of Cu enhanced the ORR performance of bi-core CuFe–Nx/C, as compared to single-core Fe–Nx/C. To fully understand the synergistic effect between Cu and Fe on this enhancement, high resolution X-ray photoelectron spectroscopy (HR-XPS) and soft X-ray absorption spectroscopy (XAS) was employed to study the electronic structure of as-synthesized electrocatalysts. The HR-XPS analysis showed that metal-nitrogen bonding was maintained and that the oxidation states of Fe and Cu were influenced by the presence of the second metal in the bi-core catalyst. The XAS data revealed that a fraction of an electron was transferred from Fe to Cu, which may help to lower the kinetic barrier during the ORR process. Based on our experimental results and four different models, we briefly discuss ORR mechanisms on these metallic catalysts.
Journal of the Chemical Society, Dalton Transactions, 2000
... Space group, C2/c, P1, P2/c, P2 1 /c, P1. ... During the course of this work, Shanmuga et al.... more ... Space group, C2/c, P1, P2/c, P2 1 /c, P1. ... During the course of this work, Shanmuga et al.18 published the structure of ligand 4, which is similar to 1, having two pendant morpholine groups, but with the tertiary butyl groups replaced by methyls. ...
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
ABSTRACT This book focuses on nanotechnology in electrocatalysis for energy applications. In part... more ABSTRACT This book focuses on nanotechnology in electrocatalysis for energy applications. In particular, the book covers nanostructured electrocatalysts for low temperature fuel cells, low temperature electrolyzers and electrochemical valorization. The function of this book is to provide an introduction to basic principles of electrocatalysis, together with a review of the main classes of materials and electrode architectures. This book will illustrate the basic ideas behind material design and provide an introductory sketch of current research focuses. The easy-to-follow three part book focuses on major formulas, concepts and philosophies. This book is ideal for professionals and researchers interested in the field of electrochemistry, renewable energy and electrocatalysis.
Journal of the Chemical Society, Dalton Transactions, 2001
... motions Valeria Amendola, Chiara Brusoni, Luigi Fabbrizzi,* Carlo Mangano, Hamish Miller, Pie... more ... motions Valeria Amendola, Chiara Brusoni, Luigi Fabbrizzi,* Carlo Mangano, Hamish Miller, Piersandro Pallavicini, Angelo Perotti and Angelo Taglietti Università di Pavia, Dipartimento di Chimica Generale, v. Taramelli, 12-27100 Pavia, Italy. E-mail: fabbrizz@unipv.it ...
We report an interesting new class of bifunctional electrocatalysts, Pd/C-CeO 2 , with excellent ... more We report an interesting new class of bifunctional electrocatalysts, Pd/C-CeO 2 , with excellent activity and stability for the hydrogen oxidation reaction (HOR) under alkaline conditions. The unique structure of palladium deposited onto a mixed support of Vulcan XC-72 carbon and CeO 2 consists of Pd metal preferable deposited on the ceria regions of the catalyst. The CeO 2-Pd interaction leads to enhanced HOR kinetics and increased stability. Here we compare catalysts with three different Pd loadings and show that the 10 wt% Pd sample has optimized activity. Hydrogen pumping and fuel cell experiments based on this catalyst show higher activities as compared to a Pd/C sample without ceria. Metal dissolution tests and identical location transmission microscopy experiments show that the catalyst stability under harsh potential cycling experiments in alkaline medium is significantly improved as compared to Pd/C, making this material one of the best options for use as highly active and highly stable electrocatalysts for the HOR in anion exchange membrane fuel cells.
Journal of CO2 Utilization, 2014
Journal of Power Sources, 2012
ABSTRACT We synthesized two “single-core” Fe–Nx/C and Cu–Nx/C electrocatalysts and a bi-core CuFe... more ABSTRACT We synthesized two “single-core” Fe–Nx/C and Cu–Nx/C electrocatalysts and a bi-core CuFe–Nx/C composite electrocatalyst using iron and copper phthalocyanine-based precursors and a high-temperature pyrolysis method. The morphology, structure, and activity toward the oxygen reduction reaction (ORR) in alkaline media were evaluated for each electrocatalyst by transmission electron microscopy (TEM), X-ray Diffraction (XRD), and the rotating ring-disk electrode (RRDE) method. Although the Cu–Nx/C catalyst showed lower catalytic activity than Fe–Nx/C, the presence of Cu enhanced the ORR performance of bi-core CuFe–Nx/C, as compared to single-core Fe–Nx/C. To fully understand the synergistic effect between Cu and Fe on this enhancement, high resolution X-ray photoelectron spectroscopy (HR-XPS) and soft X-ray absorption spectroscopy (XAS) was employed to study the electronic structure of as-synthesized electrocatalysts. The HR-XPS analysis showed that metal-nitrogen bonding was maintained and that the oxidation states of Fe and Cu were influenced by the presence of the second metal in the bi-core catalyst. The XAS data revealed that a fraction of an electron was transferred from Fe to Cu, which may help to lower the kinetic barrier during the ORR process. Based on our experimental results and four different models, we briefly discuss ORR mechanisms on these metallic catalysts.
Journal of the Chemical Society, Dalton Transactions, 2000
... Space group, C2/c, P1, P2/c, P2 1 /c, P1. ... During the course of this work, Shanmuga et al.... more ... Space group, C2/c, P1, P2/c, P2 1 /c, P1. ... During the course of this work, Shanmuga et al.18 published the structure of ligand 4, which is similar to 1, having two pendant morpholine groups, but with the tertiary butyl groups replaced by methyls. ...
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
Nanostructure Science and Technology, 2013
ABSTRACT This book focuses on nanotechnology in electrocatalysis for energy applications. In part... more ABSTRACT This book focuses on nanotechnology in electrocatalysis for energy applications. In particular, the book covers nanostructured electrocatalysts for low temperature fuel cells, low temperature electrolyzers and electrochemical valorization. The function of this book is to provide an introduction to basic principles of electrocatalysis, together with a review of the main classes of materials and electrode architectures. This book will illustrate the basic ideas behind material design and provide an introductory sketch of current research focuses. The easy-to-follow three part book focuses on major formulas, concepts and philosophies. This book is ideal for professionals and researchers interested in the field of electrochemistry, renewable energy and electrocatalysis.
Journal of the Chemical Society, Dalton Transactions, 2001
... motions Valeria Amendola, Chiara Brusoni, Luigi Fabbrizzi,* Carlo Mangano, Hamish Miller, Pie... more ... motions Valeria Amendola, Chiara Brusoni, Luigi Fabbrizzi,* Carlo Mangano, Hamish Miller, Piersandro Pallavicini, Angelo Perotti and Angelo Taglietti Università di Pavia, Dipartimento di Chimica Generale, v. Taramelli, 12-27100 Pavia, Italy. E-mail: fabbrizz@unipv.it ...