Materials For Energy: Complex Oxides And Nitrides For New Polymer Electrolyte Membrane Fuel Cell Catalysts And Supports

The currently used carbon-based catalyst supports in polymer electrolyte membrane fuel cells (PEMFC) are not sufficiently stable. New, non-carbon catalyst supports are required for large-scale commercialization of PEMFCS, and must be stable in low pH (1-2) and up to +1.5 V (vs. SHE). The material also needs to be porous and conducting (at least 0.1 S cm-1). Furthermore, the catalyst support should also be capable of strongly binding Pt or Pt-based catalysts. Previous research in the DiSalvo group has focused on doped, conducting metal oxides, yet materials with suitable conductivities have been difficult to prepare. In this work, binary and ternary transition metal nitrides are explored as potential replacements for carbon-based catalyst supports. Many nitrides have the required conductivity and chemical stability need for applications in PEMFCs, while their preparation as mesoporous solids is not well reported. In this work, Ti-based mixed metal catalyst supports were prepared as nanoparticles and thin films, and their utility for PEMFC applications investigated using a variety of material characterization techniques. Nitride compounds with Ti, Nb, Cr are conducting as both nanoparticles and thin films, and shown improved oxidation resistance when prepared as co-precipitated nanoparticles. In addition to catalyst supports, LaMO3 (M=Mn, Ni, Fe, Co) perovskites were prepared and studied as oxygen reduction catalysts for alkaline fuel cells. This work shows that these compounds favor the 2-electron reduction of O2 to H2O2 rather than full reduction to H2O. Additionally, the chemical stability of the material is discussed, and found to be unsatisfactory for applications in alkaline fuel cells.

Name thesis:degree_name

Ph. D., Chemistry and Chemical Biology

Level thesis:degree_level

Doctor of Philosophy

Discipline thesis:degree_discipline

Chemistry and Chemical Biology

Grantor

Cornell University

Year dc:date.issued

2013

Author dc:creator

• Burns, Raymond

Committee members dc:contributor.committeemember

• Van Dover, Robert B.
• Abruna, Hector D

• Fuel cell
• nitride
• catalyst
• energy
• electrochemistry
• nanoparticles
• Mesoporous
• support

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/1813/34341

OAI identifier oai:identifier

oai:ecommons.cornell.edu:1813/34341