Demonstrating Concepts in Catalysis, Renewable Energy, and Chemical Safety with the Catalytic Oxidation of Hydrogen

Abstract

A versatile and portable apparatus was developed to demonstrate exciting visual displays of catalytic phenomena that introduce basic concepts in catalysis, renewable energy, and chemical safety, in order to pique scientific curiosity in a variety of audiences including middle and high school students, undergraduate and graduate students, and the general public. The demonstration uses the platinum-catalyzed oxidation of hydrogen by oxygen as a model reaction to illustrate concepts in thermodynamics, reaction kinetics, and electrochemistry. The apparatus was designed to contain inherent safety features and the versatility to adopt several configurations to perform a wide range of experiments in classroom settings, informal science education activities, and public outreach events. Soap bubbles are used to confine small, controlled volumes (<35 cm3) of hydrogen/oxygen gas mixtures and probe the reactivity of bulk and nanoparticle forms of platinum to illustrate how high metal surface areas increase catalytic reaction rates. In parallel, a hydrogen/oxygen proton-exchange fuel cell is used to demonstrate how chemical energy released from the exergonic hydrogen oxidation reaction can be converted into electricity by using a platinum-containing electrocatalyst. With adjustments of the operating configuration and the experimental conditions of the apparatus, the demonstrations can be tailored toward target demographics of varying scientific proficiency to emphasize specific learning objectives for topics in reaction chemistry and engineering. Potential hazards and important safety precautions are addressed.