Understanding and Utilizing Block Copolymer Templates for the Preparation of Bimetallic Catalysts for Fuel Cell Applications
EMSL Project ID
48182
Abstract
The invention of the proton exchange membrane fuel cell (PEMFC) occurred over a half-century ago and, in spite of extensive developments of its science and its components, its widespread commercialization remains a challenge. Currently, improvements in the durability, performance and manufacturing cost of PEMFCs and direct alcohol fuel cells (DMFCs) are required – all of which can be addressed with advances in catalyst function. The objective of this proposal is to deepen our fundamental understanding of the block copolymer template-directed synthesis of mono- and bimetallic nanoparticle catalysts that are designed to advance PEMFC and DMFC catalysis. The proposed work will explore the underlying principles for prescribing the size, spacing and composition of nanocatalysts that are isolated from self-assembled nanostructures of block copolymers loaded with metallic ions. This pursuit will ultimately define a structure–activity relationship between nanocatalysts and their self-assembled block copolymer templates. The approach is highly flexible and allows for the preparation and screening of a variety of mono- and bimetallic catalysts nanoparticles (NPs). Consequently, we fully expect to target new and existing strategic bimetallic nanocatalysts that have a balanced composition in earth abundant and critical elements. This proposal requests access to the transmission electron microscopy (TEM) resources at the Environmental Molecular Sciences Laboratory (EMSL) at Pacific Northwest National Laboratory (PNNL) to characterize mono- and bimetallic catalysts synthesized by the block copolymer template-directed method. The proposed research will benefit from understanding the structural state of intermixed metals within nanoparticles that are routinely fabricated in the Rider group and those that are currently under development. The TEM instrumentation at EMSL is well-suited for assigning the size, shape, lattice type, nanostructure (core-shell, alloy, intermediate) and surface composition (atomic composition, lattice planes) of nanoparticle catalysts created in our work and would act to strengthen conclusions about the catalytic capabilities of the synthetic method. Throughout the 2013-2014 research year, PI (Rider) and his graduate student (Taylor) aim to visit EMSL-PNNL on a quarterly basis for 2-3 days per trip to complete the characterization.
The potential impact of the research strong from fundamental catalyst research an education standpoints. The research intends to confirm the universality and limitations of the proven catalysts preparation method (vide infra) and has been a successful program for engaging undergraduate and graduate students in the laboratory and the classroom (topics routinely discussed in PI’s General Chemistry and Materials Science courses). By confirming the relationship between the activity of synthesized catalysts with that of the polymer precursor (and any required processing steps), we expect the research program to ultimately offer the fuel cell community a new synthetic method and library of catalysts for next generation devices.
Two broad objectives define this research: the development of a fundamental understanding of templated-synthesis of (1) mono- and (2) bimetallic Pt catalysts using polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) block copolymers.
These objectives will be achieved through the following Project Goals:
1. Structure-activity relationship between monometallic Pt nanocatalysts and their self-assembled block copolymer templates.
2. Structure-activity relationship between bimetallic Pt nanocatalysts and their self-assembled block copolymer templates.
Project Details
Project type
Exploratory Research
Start Date
2013-12-02
End Date
2014-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Taylor AK, DS Perez, X Zhang, BK Pilapil, MH Engelhard, BD Gates, and DA Rider. 2017. "Block Copolymer Templated Synthesis of PtIr Bimetallic Nanocatalysts for the Formic Acid Oxidation Reaction." Journal of Materials Chemistry A 5(40):21514-21527. doi:10.1039/c7ta06458f