OXYGEN ABSORBER

摘要

An oxygen absorber containing a fluorite-type porous cerium oxide which is represented by the formula: CeOx (wherein x is a positive number of less than 2) and has reversible oxygen vacancies.  The oxygen absorber has a specific surface area of 0.6 to 1.8m2/g and a median diameter of pores of 1.6 to 5.3µm.  The cerium oxide to be used in the oxygen absorber can be produced by firing a cerium-containing salt in the atmosphere at 500 to 1400°C for 1 to 20 hours to form a fluorite-type porous cerium oxide, and then firing the porous cerium oxide in a reducing atmosphere having a hydrogen concentration equal to or above the lower explosion limit at 700 to 1100°C for 1 to 3 hours to draw oxygen from the cerium oxide and thus form a fluorite-type cerium oxide which is represented by the formula: CeOx and has reversible oxygen vacancies.