A method for preparing an ordered cross-stacked metal oxide nanowire array is provided. The method includes the following steps: conducting synthesis by using an amphiphilic diblock copolymer as a structure directing agent, tetrahydrofuran (THF) as a solvent and polyoxometalates (POMs) as an inorganic precursor, where the diblock copolymer can interact with POMs via an electrostatic force to form a core-shell cylindrical micelle in the solvent, which self-assembles to form an ordered multilayer-crossed organic-inorganic composite nanostructure during an evaporation process; the template is removed by calcination in air, thereby obtaining ordered and crossed metal oxide nanowires with various elements doping. The nanowire array material has a high specific surface area, a high crystallinity, and realizes uniform doping of heteroatoms.

A spray pyrolysis system and method are described for manufacture of mixed metal oxide compositions, e.g., mixed metal oxide catalyst compositions having utility for gas processing applications such as hydrogenation, dehydrogenation, reduction, and oxidation. Mixed metal oxide automotive exhaust catalyst compositions produced by such system and method achieve a substantial reduction in temperatures required for removal of automotive exhaust pollutant species, as compared to catalyst produced by conventional batch precipitation techniques. The spray pyrolysis system and method enable catalytic metal(s) to be integrally incorporated in the mixed metal oxide composition, thereby obviating a separate catalytic metal impregnation operation.

A circulating fluidized bed (CFB) furnace for heating and/or calcination of a material is disclosed. A process for calcination of a material is further.