Ultrafine iron powder was found to be able to remove oxygen from argon. The affinity of iron to oxygen is very high, and oxygen can be removed to concentrations well below 0.2 ppm. The successive experimental runs indicated that the sorbent matrix is not deactivated and maintains high oxygen loading capacities. The spent material can be easily regenerated in a stream of hydrogen at low temperatures. Iron powder was prepared by the thermal decomposition from organic precursors. The sorbent can be easily packed in an adsorption column. The process described here can be scaled up for industrial use.