The invention provides processes for selectively oxidizing carbon monoxide from
an input gas stream that contains carbon monoxide, oxygen and hydrogen. The process
includes the step of contacting the input gas stream with a preferential oxidation
catalyst. The preferential oxidation catalysts are copper-based catalysts containing
low concentrations of platinum group metals. In some embodiments, the processes
of the invention are conducted using preferential oxidation catalysts having an
oxide support on which is dispersed copper or an oxide thereof, a platinum group
metal and a reducible metal oxide. In other embodiments, the processes of the invention
are conducted with a preferential oxidation catalysts having a cerium oxide support
on which is dispersed copper or an oxide thereof and a platinum group metal.
