Self-assembling solid oxide fuel cell materials: Mesoporous yttria-zirconia and metal-yttria-zirconia solid solutions

A new class of mesoporous (nickel/platinum)-yttria-zirconia materials, deno ted meso-(Ni/Pt)YZ, which may have utility as electrode material in solid o xide fuel cells (SOFCs), have been synthesized by aqueous co-assembly of gl ycometalates and metal complexes with a surfactant template. These material s form as solid solutions with compositions that can be tuned over the rang e 12-56 atom % yttrium and 10-30 atom % nickel or 1-10 wt % platinum. The m icrostructure of the channel wall is nanocrystalline yttria-zirconia (YZ) a nd nickel/platinum is incorporated as metal oxide/metal clusters with diame ters comparable to the size of the pores depending on the degree of loading of the metal precursor. Calcination in air of as-synthesized meso-(Ni/Pt)Y Z materials causes the channel walls to crystallize and thicken as the imbi bed organics are lost. It is the relatively thick, YZ nanocrystalline walls which are believed to be responsible for the impressive 800 degrees C ther mal stability of meso-(Ni/Pt)YZ. This new class of binary and ternary mesop orous materials display the highest recorded surface area of any known form of (metal)-yttria-stabilized-zirconia. A narrow mesopore size distribution , nanocrystalline channel walls, and high thermal stability may lead to sig nificant improvements in fuel/oxidant mass transport, oxide ion mobility, e lectronic conductivity, and charge transfer at the triple-phase-boundary re gion of SOFC electrodes. It may also enable a reduction in the operating te mperature of the SOFC.