Abstract: Au/FeOx/Al2O3 showed more active and stable than Au/Al2O3 in CO oxidation at low temperature. Moisture enhanced the activity of the nano-sized gold catalyst, and higher CO conversion appeared at water partial pressure of 550-1600 Pa in the feed gas. The catalyst was deactivated fast and irreversibly in dry feed gas but slow and reversibly in saturated vapor. The gold particle size increased in the catalyst that was deactivated by saturated vapor. The promoters had no effect on water resistance but had a visible effect on the resistance to H2S or SO2. The main reason of deactivation was the appearance of sulfide or sulfate on the catalyst surface.

Key words: nano-sized particle, gold, composite support, supported catalyst, carbon monoxide, oxidation, moisture, sulfur, poison