Engineering Commons^™

Rate-Determining Step And Active Sites Probing For Platinum-Group-Metal Free Cathode Catalyst In Fuel Cell, Yechuan Chen

Chemical and Biological Engineering ETDs

With the increasing demand on renewable energy, the fuel cell has attracted more and more interests because of its large power density and controllable size. However, the insufficiency of element abundance and unstable expensive price of conventional platinum-based electrocatalysts used in anode and cathode makes it essential to find their substitutes. As one of the most promising candidates to be used in cathode for oxygen reduction reaction (ORR), iron-nitrogen-carbon (Fe-N-C) catalysts have been widely investigated and get commercialized recently, but still lacks comprehensive understanding on the kinetic mechanism.

This dissertation has been divided into three parts with a discussion on …

An Investigation Of The Effects Of The Second Pyrolysis On The Chemistry, Morphology, And Performance Of Iron-Nicarbazin Catalysts, Elizabeth B. Weiler

Chemical and Biological Engineering ETDs

Proton exchange membrane fuel cells offer a cost-effective, environmentally friendly, and sustainable alternative to petroleum-based power sources to the transportation sector. However, slow electrochemical reactions at the cathode of these fuel cell prevent the technology from being competitive. Iron-nitrogen-carbon based catalysts have emerged as a viable answer to this problem, yet further progress is needed to improve their performance beyond that of current state-of-the-art platinum-based catalysts, which are economically and geopolitically impractical to be a final solution. Currently, a two-step high temperature pyrolysis method has proven a promising way to synthesize iron-nitrogen-carbon catalysts for optimized performance, but there is a …

Anodic Catalysts For Anion Exchange Membrane Fuel Cells, Aaron Joseph Roy

Chemical and Biological Engineering ETDs

With a limited availability of energy resources from petroleum and other fossil fuels, as well as growing concerns relating to the environmental implications of fossil fuel emissions, non-carbon fuels which can be utilized in proton and anion exchange membrane fuel cells (PEMFC’s/AEMFC’s), such as hydrogen and hydrazine hydrate (HH), are becoming more attractive as alternative fuels. Historically, platinum and platinum group metal catalysts (PGM) have been used as cathode and anode catalyst materials for both PEMFC’s and AEMFC’s. Although these catalysts are the highest performing catalysts available for the conversion of hydrogen energy in fuel cells, the limited availability and …

Graphite And Graphene-Oxide Based Pgm-Free Model Catalysts For The Oxygen Reduction Reaction, Joseph Henry Dumont

Nanoscience and Microsystems ETDs

The world currently relies heavily on fossil fuels such as coal, oil, and natural gas for its energy. Fossil fuels are non-renewable, that is, they draw on finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve. One alternative source of energy are fuel cells, electrochemical devices that convert chemical energy to cleanly and efficiently produce electricity. They can be used in a wide range of applications, including transportation, stationary, portable and emergency power sources. Their development has been slowed by the high cost of PGM electrocatalysts needed at both electrodes as well as sluggish …

A Study Of Iron-Nitrogen-Carbon Fuel Cell Catalysts: Chemistry – Nanostructure – Performance, Michael J. Workman

Nanoscience and Microsystems ETDs

Fuel cells have the potential to be a pollution-free, low-cost, and energy efficient alternative to the internal combustion engine for transportation and small-scale stationary power applications. The current state of fuel cell technology has already achieved two of these three lofty goals. The remaining barrier to wide-scale deployment is the high cost, which is primarily caused by dependence on large amounts of platinum to catalyze the energy conversion reactions. To overcome this barrier and facilitate the integration of fuel cells into mainstream applications, research into a new class of catalyst materials that do not require platinum is needed.

There has …