Advanced Technology

Preferential Oxidation (PROX) Catalyst For Carbon Monoxide

PROX = Preferential Oxidation
This catalyst is used to selectively oxidize carbon monoxide from reforming gas in PEFC.

In proton-exchange membrane fuel cells (PEFCs), a reforming gas that contains hydrogen (H2) is used. This reforming gas also contains a certain amount of carbon monoxide (CO). Because CO poison electrodes, and deteriorate battery performance, the concentration of CO in the reforming gas should be below 10 ppm. PROX catalyst is a catalyst to selectively oxidize CO in reforming gas to carbon dioxide (CO2).


  • High activity even at a high space velocity owing to highly dispersed catalytic precious metal 
  • Activity is maintained at a wide range of temperatures from low to high 
  • Despite a low precious metal content, the catalysts maintain a high level of activity, which enables us to offer catalysts at low cost 


ProductComponentPrecious metal
content (wt%)
TSSA-2Ru, Al2O30.17(2.0g/L)High activity at
high temperature
TSSA-5Ru, Al2O30.40(4.8g/L)High activity at
low temperature

(Both products shaped in a Φ1mm to 3 mm pellet)

How to use PROX catalysts

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