A method for the removal of trace quantities (0.2 to 10 ppm) of carbon monoxide in commercial hydrogen using a temperature-swing-adsorption system with 0.5 wt% Pt/Al2O3 adsorbent has been investigated. The adsorbent could be regenerated by treatment with air at 200 degreesC to 250 degreesC or by treatment with hydrogen at 270 degreesC. The breakthrough curves have been described by a model which considers both the external-film resistance and the intraparticle diffusion resistance. The model has been validated at the high gas velocities expected in a commercial plant.