Abstract: A method for the preparing pure, thermally stable and high surface area ceria is described, wherein the ceria maintains a surface area of 12 m2/g after calcination at 980° C. in air for 4 hours. In the method, an aqueous solution containing Ce3+, Mg2+, organic acid and organic polymer is prepared and then evaporated to obtain a gel. The gel is calcined to obtain a mixed oxide, and then MgO is leached from the mixed oxide with a solvent to obtain raw ceria. The raw ceria is then washed, filtered and dried to obtain a ceria product.

Abstract: A method for the preparing pure, thermally stable and high surface area ceria is described, wherein the ceria maintains a surface area of 12 m2/g after calcination at 980° C. in air for 4 hours. In the method, an aqueous solution containing Ce3+, Mg2+, organic acid and organic polymer is prepared and then evaporated to obtain a gel. The gel is calcined to obtain a mixed oxide, and then MgO is leached from the mixed oxide with a solvent to obtain raw ceria. The raw ceria is then washed, filtered and dried to obtain a ceria product.

Abstract: A solid electrolyte based on magnesia-doped ceria is described, having a composition represented by general formula Ce1-x-yMxMgyO2-d, wherein M stands for Y, Ca or Sr, and the ranges of x and y are defined by the inequalities of 0.01?x<0.3, 0.01?y?0.6 and 0.02?x+y?0.7. The composition can be formed into a sintered body suitably used as an oxygen-ion conducting solid electrolyte of an intermediate-temperature solid oxide fuel cell or other electrochemical devices. The solid electrolyte with suitable values of x and y have low cost, high stability and acceptable ionic conductivity as compared with similarly prepared Gd-doped ceria electrolyte.