Combustion Synthesis of Membranes for Steam Reforming of Dimethyl Ether

We have developed a new generation of porous metal-ceramic membranes by using self-propagating high-temperature synthesis in vacuum on the basis of a mixture of a nickel powder (average particle size of 100 μm), cobalt oxide powder (average particle size of 10–15 nm), and aluminum powder (average particle size of 5–10 μm). In combustion synthesis, a membrane frame is formed from large particle fractions with open pores with size of 2.6–5.1 μm, so that it leads to an increase in membrane permeability and to a large consumption of the substrate. The synthesis thus produces porous metal-ceramic catalytically active membranes containing nanoparticles of nickel and cobalt in surface pore layers with size of 10–20 nm. The complete conversion of dimethyl ether is achieved at 450°C, producing synthesis gas and ultrahigh-purity hydrogen.