Theoretical Design of CO Poisoning Resistant Pt Catalysts through Ge Alloying

Abstract

The rapid growth of population over the last decades has supposed a vast increment in the consumption of fossil fuels to meet our energy demands. This overconsumption has accelerated the emission of greenhouse gases, acidification of oceans, deforestation and socio-economical differences. As a result, there is an urge to transition to a greener energy economy. In this context, the proton exchange membrane fuel cell (PEMFC) has gained a lot of attention recently as a more sustainable energy source. This device generates electricity by oxydizing a H2 fuel, being water the only byproduct. Nonetheless, several issues must be solved before such device can be commerzialized. First, the electrochemical reactions occurring inside the PEMFC are inefficient. This makes mandatory the use of very active catalysts. Up to date, Pt remains the state-ofthe- art catalyst. Unfortunately, this precious metal is very scarce and expensive. Second, the H2 manufactured by current industrial processes is contaminated with trace amounts of CO, a well-known catalyst poison. The Pt surface gets covered by a CO layer, hindering the reaction; over a few catalytic cycles the catalyst can be left completely useless. Hence, effective solutions are required to design cheaper catalysts resistant to CO poisoning.