This reaction is a considerable subject area of research with implications for fuel cell design.
Its main utility lies in the removal of carbon monoxide (CO) from the fuel cell's feed gas. CO poisons the catalyst of most low-temperature fuel cells.
Carbon monoxide is often produced as a by-product from steam reforming of hydrocarbons, which produces hydrogen and CO.
It is possible to consume most of the CO by reacting it with steam in the water-gas shift reaction:
:CO + HO  H + CO
The water-gas shift reaction can reduce CO to 1% of the feed, with the added benefit of producing more hydrogen, but not eliminate it completely.
To be used in a fuel cell, feed gas must have CO below 10 ppm.