Date of Graduation

Spring 2017

Document Type

Honors Research Project

Degree Name

Bachelor of Science

Major

Chemical Engineering - Cooperative Education

Research Sponsor

Dr. Zhenmeng Peng

First Reader

Dr. Nic Leipzig

Second Reader

Dr. Chelsea Monty

Abstract

This study evaluates the electrochemical activity of several compositions of platinum-rhodium alloys on carbon support to identify potential replacements for the expensive platinum electrocatalysts currently used in direct methanol fuel cells (DMFCs). The electrochemical active surface areas (ECSAs) of each sample were determined using cyclic voltammetry (CV) in a 0.5 M H2SO4 solution to normalize CV currents generated in the methanol oxidation reaction (MOR). The activity of five compositions was tested; Pt3Rh, Pt2Rh, PtRh, Pt2Rh, and Pt3Rh. 100 mg of each catalyst was synthesized at 10% by weight platinum loading using a surfactant-free impregnation technique. TEM images were taken of one sample to examine morphology and confirm alloying of the two metals. A volcano-like relationship was found between decreasing platinum loading and electrochemical activity, with a peak seen with the Pt2Rh sample at 0.66 mA/cm2. This value is higher than a similarly prepared commercial platinum catalyst which had an activity of 0.6 mA/cm2. These findings indicate that Pt2Rh has the potential to be better suited for use in DMFCs than commercial platinum, and could be used to bring down the cost of DMFCs and make green energy one step closer to reality.

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