(32d) A Novel Membrane Reactor for Electrochemical Preferential Oxidation (ECPrOx) of CO

Steam reforming constitutes a major source of hydrogen production. A typical reformate from a steam reformer followed by water-gas-shift (WGS) contains roughly 75% H2, 24% CO2, and 5000-10000 ppm CO. However, CO present in the reformate poisons platinum electro-catalyst and adversely affects the fuel cell performance. Thus, preferential oxidation (PrOx) is used to selectively oxidize CO. Despite being universally adopted in fuel reformers, the current PrOx technology used to reduce the CO is in fact, cumbersome and bulky. Another limitation is the poor selectivity of the PrOx reactor for CO oxidation over H2.

An entirely novel membrane reactor with the configuration of a fuel cell, namely ECPrOx, i.e., electrochemical preferential oxidation of CO is being developed in our laboratory. This membrane-based process exploits the oscillatory CO electro-oxidation by utilizing electric potential to cleanse CO from reformate. Here selective CO electro-oxidation is achieved at the anode by rendering the process electrochemical. In addition, supplemental power is produced with no H2 wasted.

The electrochemical device has direct application in on-board reforming process for fuel cell applications and the potential to replace both WGS reaction and PrOx.