IngentaConnect A New Palladium-Based Catalyst for Methanol Steam Reforming in a ...

Authors: Ilinich, Oleg; Liu, Ye; Castellano, Christopher; Koermer, Gerald; Moini, Ahmad; Farrauto, Robert

Source: Platinum Metals Review, Volume 52, Number 3, July 2008 , pp. 134-143(10)

Abstract:

A novel palladium-based catalyst has been developed for use in a miniature fuel cell power source for portable applications, incorporating a polymer electrolyte membrane (PEM) fuel cell. Hydrogen, which is the fuel for the cell, is produced in a ceramic microreactor via the catalytic reaction of methanol steam reforming: CH₃OH + H₂O → 3H₂ + CO₂. The need for a new catalyst in this application is driven by the limitations of traditional particulate catalysts based on copper oxide, zinc oxide and alumina (Cu-Zn-Al catalysts), which have low thermal stability and high sensitivity towards air and condensing steam. These features result in a declining activity and mechanical integrity of Cu-Zn-Al catalysts under the frequent start-stop conditions typical of the operational mode of the miniature power source. The new Pd-based catalyst has activity and selectivity similar to those of Cu-Zn-Al catalysts, but is more durable and stable under the duty cycle conditions of a portable power source. In the microreformer, the catalyst is washcoated directly on the walls of the steam reforming section, providing favourable conditions for efficient heat transfer between the heat-generating catalytic combustion section of the microreformer and its heat-consuming steam reforming section.

A New Palladium-Based Catalyst for Methanol Steam Reforming in a Miniature Fuel Cell Power Source