Related Experiment Video
Updated: Jul 4, 2026
12:12
On the Preparation and Testing of Fuel Cell Catalysts Using the Thin Film Rotating Disk Electrode Method
Published on: March 16, 2018
Estimation of the hamaker coefficient for a fuel-cell-supported catalyst system
Ram Subbaraman1, Tom Zawodzinski, J A Mann
1Department of Chemical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Langmuir : the ACS Journal of Surfaces and Colloids
|June 28, 2008
Summary
This study estimates Hamaker coefficients for nanoparticle-support systems in polymer electrolyte membrane fuel cells, revealing insights into catalyst adhesion and cohesion. These findings impact supported catalyst structure and performance.
Area of Science:
- Materials Science
- Physical Chemistry
- Electrochemistry
Background:
- Polymer electrolyte membrane fuel cells (PEMFCs) rely on supported nanoparticle catalysts.
- Understanding nanoparticle-support interactions is crucial for catalyst stability and efficiency.
- Van der Waals forces significantly influence catalyst structure and performance.
Purpose of the Study:
- To estimate Hamaker coefficients for common nanoparticle-support systems in PEMFCs.
- To quantify interaction energies, nanoparticle cohesion, and adhesion on supports.
- To discuss the implications of van der Waals forces on supported catalyst properties.
Main Methods:
- Estimation of Hamaker coefficients using Lifshitz theory.
- Analysis of experimental data for interaction energies and adhesion.
- Calculation of bulk platinum properties from optical spectra.
- Measurement of optical properties for relevant systems.
Main Results:
- Hamaker coefficients were estimated for various nanoparticle-support systems.
- Interaction energies, nanoparticle cohesion, and adhesion were quantified.
- Comparison between bulk platinum and nanoparticle properties was established.
- The Lifshitz theory algorithm was validated with known materials.
Conclusions:
- Van der Waals forces play a critical role in determining the structural properties of supported catalysts.
- The estimated Hamaker coefficients provide valuable data for designing stable and efficient PEMFC catalysts.
- This work offers a deeper understanding of nanoparticle-support interactions in fuel cell applications.
Related Concept Videos
03:12Batteries and Fuel Cells
A battery is a galvanic cell that is used as a source of electrical power for specific applications. Modern batteries exist in a multitude of forms to accommodate various applications, from tiny button batteries such as those that power wristwatches to the very large batteries used to supply backup energy to municipal power grids. Some batteries are designed for single-use applications and cannot be recharged (primary cells), while others are based on conveniently reversible cell reactions that...
01:22Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...
02:50Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
01:27Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
02:13Reduction of Alkenes: Catalytic Hydrogenation
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the surface of...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the surface of...
02:46Calculating the Equilibrium Constant
The equilibrium constant for a reaction is calculated from the equilibrium concentrations (or pressures) of its reactants and products. If these concentrations are known, the calculation simply involves their substitution into the Kc expression.
For example, gaseous nitrogen dioxide forms dinitrogen tetroxide according to this equation:
For example, gaseous nitrogen dioxide forms dinitrogen tetroxide according to this equation: