One undesired reaction which takes place alongside CO oxidation, and that should be minimized, is the hydrogen oxidation to water. In a conventional PROX reactor, for example, a catalytic oxidation selectivity of 50% equates to a loss of approximately 2.7% in fuel efficiency for a 2% CO reformate stream [15]. A large consumption of hydrogen is undesired since it decreases the power generation of the fuel cell [16].