Abstract: Activated carbon filters containing transition metals, are prepared by (a) exchanging the transition metal with a cellulose ion exchange material to produce a cellulose material containing the transition metal; (b) charring of the product of (a); activating the product of (b) to form an activated carbon filter having a pore network throughout; and removing surface carbon substantially throughout the pore network of the filter formed in (c). Methods of filtering an atmosphere containing a gaseous contaminant by passing the contaminated atmosphere through a filter made by this process are described.