Abstract: A membrane for use in a high temperature gas processing system and method for making the same. The membrane includes a dense, gas impermeable layer and a first and second porous layer, wherein each of the first and second porous layers is a ceramic oxide material having a non-symmetrical load bearing skeleton of a plurality of pores having a graded porosity. Each porous layer provides a reduction of an oxygen partial pressure gradient across the dense layer and reduces resultant stresses in the dense layer that are small compared to its strength thereby improving long term mechanical durability of the dense layer.