Hamish Miller - Profile on Academia.edu (original) (raw)

Papers by Hamish Miller

Research paper thumbnail of Energy & chemicals from renewable resources by electrocatalysis

The selective production of chemicals from renewable resources with contemporaneous release of en... more The selective production of chemicals from renewable resources with contemporaneous release of energy is perhaps one of the most desired targets of sustainable chemistry. Here, we report an overview of our recent research efforts, where we have demonstrated that this can be achieved using renewable alcohols, by means of two electrochemical devices: direct fuel cells and electrolyzers. In either case, an aqueous solution of the fuel in the anode compartment is oxidized on a nanostructured electrocatalyst that promotes selectively the partial oxidation of the anolyte with high stability and fast kinetics. We have found that anode electrocatalysts based on nanosized Pd particles, alone or promoted by Ni-Zn phases as well as by CeO 2 or TiO 2 , are able to accomplish this goal in alkaline environment when used in conjunction with commercially available cathode electrocatalysts and solid or liquid electrolytes. In an electrolyzer, containing an anode electrocatalyst similar to that employable in a DAFC, the electrolyte may be either an anion exchange-membrane or a solution of an alkali metal hydroxide (NaOH or KOH, for example) and the alcohol is converted to the corresponding alkali metal carboxylate, while hydrogen gas is produced at the cathode upon water reduction.

Research paper thumbnail of Polyketone Nanocomposites by Palladium-Catalyzed Ethylene-Carbon Monoxide-(Propene) Co(Ter)polymerization Inside an Unmodified Layered Silicate

e-Polymers, 2006

Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt %... more Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt % were prepared in situ either by copolymerization of ethylene and CO or by terpolymerization of ethylene, propene and CO using a palladium(II) catalyst modified with 1,3-bis(diphenylphosphino)propane. This catalytic system is active in polar media and allowed to produce nanocomposites starting from unmodified Na-montmorillonite in water-methanol solutions. The morphological analysis, performed on samples with less than 40 wt % silicate by XRD and TEM, showed the formation of either intercalated or exfoliated (nanocomposite) structures, depending on the initial amount of the layered silicate in the reactor as well as the presence of propene as comonomer. Improved thermal stability of the hybrid materials, as compared to the corresponding organic polymers, was shown by TGA. A preliminary study of the blending of some polyketone nanocomposites with polyamide (nylon-6) was carried out by melt mixing at high temperature in a Brabender mixer.

Research paper thumbnail of Highly active nanostructured palladium-ceria electrocatalysts for the hydrogen oxidation reaction in alkaline medium

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.

Research paper thumbnail of Revisiting strontium-doped lanthanum cuprate perovskite for the electrochemical reduction of CO2

Journal of CO2 Utilization, 2014

Research paper thumbnail of Electrochemical and spectroscopic study of novel Cu and Fe-based catalysts for oxygen reduction in alkaline media

Electrochemical and spectroscopic study of novel Cu and Fe-based catalysts for oxygen reduction in alkaline media

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.

Research paper thumbnail of Highly Efficienty Palladium-Based ANODE Electrocatalyts For Direct Ethylene Glycol and Glycerol FUEL CELLS

Highly Efficienty Palladium-Based ANODE Electrocatalyts For Direct Ethylene Glycol and Glycerol FUEL CELLS

Research paper thumbnail of Supramolecular assemblies from ditopic ligands and transition metal salts †

Supramolecular assemblies from ditopic ligands and transition metal salts †

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. ...

Research paper thumbnail of Molecular Complexes in Electrocatalysis for Energy Production and Storage

Molecular Complexes in Electrocatalysis for Energy Production and Storage

Nanostructure Science and Technology, 2013

Research paper thumbnail of Electrochemical Devices for Energy Conversion and Storage

Electrochemical Devices for Energy Conversion and Storage

Nanostructure Science and Technology, 2013

Research paper thumbnail of Factors Affecting Design

Factors Affecting Design

Nanostructure Science and Technology, 2013

Research paper thumbnail of Monolayer Decorated Core Shell and Hollow Nanoparticles

Monolayer Decorated Core Shell and Hollow Nanoparticles

Nanostructure Science and Technology, 2013

Research paper thumbnail of Shape and Structure-Controlled Metal Nanoparticles

Shape and Structure-Controlled Metal Nanoparticles

Nanostructure Science and Technology, 2013

Research paper thumbnail of A Bird’s Eye View of Energy-Related Electrochemistry

A Bird’s Eye View of Energy-Related Electrochemistry

Nanostructure Science and Technology, 2013

Research paper thumbnail of Nanotechnology in Electrocatalysis for Energy

Nanotechnology in Electrocatalysis for Energy

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.

Research paper thumbnail of Recent Technological Progress in CO 2 Electroreduction to Fuels and Energy Carriers in Aqueous Environments

Research paper thumbnail of Self-Sustainable Production Of Hydrogen and Chemicals From Renewable Alcohols By Alkaline Electrolysis

Self-Sustainable Production Of Hydrogen and Chemicals From Renewable Alcohols By Alkaline Electrolysis

Research paper thumbnail of Electrochemical Conversion of Carbon Dioxide to Methane By Depolarized Anode Alkaline Membrane CO 2 Electrolizer (DAAM-CE)

Electrochemical Conversion of Carbon Dioxide to Methane By Depolarized Anode Alkaline Membrane CO 2 Electrolizer (DAAM-CE)

Research paper thumbnail of Direct Alcohol Fuel Cells: Toward the Power Densities of Hydrogen-Fed Proton Exchange Membrane Fuel Cells

Research paper thumbnail of Molecular rearrangements controlled by pH-driven Cu2+ motions

Molecular rearrangements controlled by pH-driven Cu2+ motions

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 ...

Research paper thumbnail of Polyketone Nanocomposites by Palladium-Catalyzed Ethylene-Carbon Monoxide-(Propene) Co(Ter)polymerization Inside an Unmodified Layered Silicate

e-Polymers, 2006

Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt %... more Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt % were prepared in situ either by copolymerization of ethylene and CO or by terpolymerization of ethylene, propene and CO using a palladium(II) catalyst modified with 1,3-bis(diphenylphosphino)propane. This catalytic system is active in polar media and allowed to produce nanocomposites starting from unmodified Na-montmorillonite in water-methanol solutions. The morphological analysis, performed on samples with less than 40 wt % silicate by XRD and TEM, showed the formation of either intercalated or exfoliated (nanocomposite) structures, depending on the initial amount of the layered silicate in the reactor as well as the presence of propene as comonomer. Improved thermal stability of the hybrid materials, as compared to the corresponding organic polymers, was shown by TGA. A preliminary study of the blending of some polyketone nanocomposites with polyamide (nylon-6) was carried out by melt mixing at high temperature in a Brabender mixer.

Research paper thumbnail of Energy & chemicals from renewable resources by electrocatalysis

The selective production of chemicals from renewable resources with contemporaneous release of en... more The selective production of chemicals from renewable resources with contemporaneous release of energy is perhaps one of the most desired targets of sustainable chemistry. Here, we report an overview of our recent research efforts, where we have demonstrated that this can be achieved using renewable alcohols, by means of two electrochemical devices: direct fuel cells and electrolyzers. In either case, an aqueous solution of the fuel in the anode compartment is oxidized on a nanostructured electrocatalyst that promotes selectively the partial oxidation of the anolyte with high stability and fast kinetics. We have found that anode electrocatalysts based on nanosized Pd particles, alone or promoted by Ni-Zn phases as well as by CeO 2 or TiO 2 , are able to accomplish this goal in alkaline environment when used in conjunction with commercially available cathode electrocatalysts and solid or liquid electrolytes. In an electrolyzer, containing an anode electrocatalyst similar to that employable in a DAFC, the electrolyte may be either an anion exchange-membrane or a solution of an alkali metal hydroxide (NaOH or KOH, for example) and the alcohol is converted to the corresponding alkali metal carboxylate, while hydrogen gas is produced at the cathode upon water reduction.

Research paper thumbnail of Polyketone Nanocomposites by Palladium-Catalyzed Ethylene-Carbon Monoxide-(Propene) Co(Ter)polymerization Inside an Unmodified Layered Silicate

e-Polymers, 2006

Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt %... more Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt % were prepared in situ either by copolymerization of ethylene and CO or by terpolymerization of ethylene, propene and CO using a palladium(II) catalyst modified with 1,3-bis(diphenylphosphino)propane. This catalytic system is active in polar media and allowed to produce nanocomposites starting from unmodified Na-montmorillonite in water-methanol solutions. The morphological analysis, performed on samples with less than 40 wt % silicate by XRD and TEM, showed the formation of either intercalated or exfoliated (nanocomposite) structures, depending on the initial amount of the layered silicate in the reactor as well as the presence of propene as comonomer. Improved thermal stability of the hybrid materials, as compared to the corresponding organic polymers, was shown by TGA. A preliminary study of the blending of some polyketone nanocomposites with polyamide (nylon-6) was carried out by melt mixing at high temperature in a Brabender mixer.

Research paper thumbnail of Highly active nanostructured palladium-ceria electrocatalysts for the hydrogen oxidation reaction in alkaline medium

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.

Research paper thumbnail of Revisiting strontium-doped lanthanum cuprate perovskite for the electrochemical reduction of CO2

Journal of CO2 Utilization, 2014

Research paper thumbnail of Electrochemical and spectroscopic study of novel Cu and Fe-based catalysts for oxygen reduction in alkaline media

Electrochemical and spectroscopic study of novel Cu and Fe-based catalysts for oxygen reduction in alkaline media

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.

Research paper thumbnail of Highly Efficienty Palladium-Based ANODE Electrocatalyts For Direct Ethylene Glycol and Glycerol FUEL CELLS

Highly Efficienty Palladium-Based ANODE Electrocatalyts For Direct Ethylene Glycol and Glycerol FUEL CELLS

Research paper thumbnail of Supramolecular assemblies from ditopic ligands and transition metal salts †

Supramolecular assemblies from ditopic ligands and transition metal salts †

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. ...

Research paper thumbnail of Molecular Complexes in Electrocatalysis for Energy Production and Storage

Molecular Complexes in Electrocatalysis for Energy Production and Storage

Nanostructure Science and Technology, 2013

Research paper thumbnail of Electrochemical Devices for Energy Conversion and Storage

Electrochemical Devices for Energy Conversion and Storage

Nanostructure Science and Technology, 2013

Research paper thumbnail of Factors Affecting Design

Factors Affecting Design

Nanostructure Science and Technology, 2013

Research paper thumbnail of Monolayer Decorated Core Shell and Hollow Nanoparticles

Monolayer Decorated Core Shell and Hollow Nanoparticles

Nanostructure Science and Technology, 2013

Research paper thumbnail of Shape and Structure-Controlled Metal Nanoparticles

Shape and Structure-Controlled Metal Nanoparticles

Nanostructure Science and Technology, 2013

Research paper thumbnail of A Bird’s Eye View of Energy-Related Electrochemistry

A Bird’s Eye View of Energy-Related Electrochemistry

Nanostructure Science and Technology, 2013

Research paper thumbnail of Nanotechnology in Electrocatalysis for Energy

Nanotechnology in Electrocatalysis for Energy

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.

Research paper thumbnail of Recent Technological Progress in CO 2 Electroreduction to Fuels and Energy Carriers in Aqueous Environments

Research paper thumbnail of Self-Sustainable Production Of Hydrogen and Chemicals From Renewable Alcohols By Alkaline Electrolysis

Self-Sustainable Production Of Hydrogen and Chemicals From Renewable Alcohols By Alkaline Electrolysis

Research paper thumbnail of Electrochemical Conversion of Carbon Dioxide to Methane By Depolarized Anode Alkaline Membrane CO 2 Electrolizer (DAAM-CE)

Electrochemical Conversion of Carbon Dioxide to Methane By Depolarized Anode Alkaline Membrane CO 2 Electrolizer (DAAM-CE)

Research paper thumbnail of Direct Alcohol Fuel Cells: Toward the Power Densities of Hydrogen-Fed Proton Exchange Membrane Fuel Cells

Research paper thumbnail of Molecular rearrangements controlled by pH-driven Cu2+ motions

Molecular rearrangements controlled by pH-driven Cu2+ motions

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 ...

Research paper thumbnail of Polyketone Nanocomposites by Palladium-Catalyzed Ethylene-Carbon Monoxide-(Propene) Co(Ter)polymerization Inside an Unmodified Layered Silicate

e-Polymers, 2006

Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt %... more Composites from Na-montmorillonite with a content in inorganic material ranging from 3 to 98 wt % were prepared in situ either by copolymerization of ethylene and CO or by terpolymerization of ethylene, propene and CO using a palladium(II) catalyst modified with 1,3-bis(diphenylphosphino)propane. This catalytic system is active in polar media and allowed to produce nanocomposites starting from unmodified Na-montmorillonite in water-methanol solutions. The morphological analysis, performed on samples with less than 40 wt % silicate by XRD and TEM, showed the formation of either intercalated or exfoliated (nanocomposite) structures, depending on the initial amount of the layered silicate in the reactor as well as the presence of propene as comonomer. Improved thermal stability of the hybrid materials, as compared to the corresponding organic polymers, was shown by TGA. A preliminary study of the blending of some polyketone nanocomposites with polyamide (nylon-6) was carried out by melt mixing at high temperature in a Brabender mixer.