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Influences of solid-acid catalyst on DME steam reforming (DME SR) and DME hydrolysis for hydrogen production were investigated. Series of zeolite (JRC-ZHM20(5), JRC-ZHM90(1) as H-mordenite type and JRC-Z5-90H(1) as ZSM-5 type) and of alumina (ALO8, TA1301, TA3301, DK503, NKHD24, NKHO24 and NK324) were used as acidic catalysts for DME hydrolysis. The composite catalysts of the acidic catalyst and CuFe 2 O 4 spinel catalyst were employed for DME SR. DME SR activity strongly depended on the acidic catalyst that is active for DME hydrolysis. The hydrolysis of DME, the rate-determining step in DME SR, is equilibrium-controlled. Zeolite exhibited high activity for DME SR at a low temperature range of 200-275 o C, since the hydrolysis could effectively proceed over strong Br∅nsted acid-sites approaching its equilibrium. Alumina possessing Lewis acid-sites was active for DME hydrolysis in the higher temperature range from 275 to 450 o C. CO 2 and CO with relatively small amounts of CH 4 were found as primary carbon-containing compounds when alumina was used as the acidic catalyst. In the case of zeolite, besides those carbon compounds, C 3 H 8 , i-C 4 H 10 , and n-C 4 H 10 were detected during SR and hydrolysis of DME. It was found that not only the acid amount of the acidic catalysts, but also the acid strength and the type of acid site definitely affected the steam reforming and hydrolysis activity. γ-Alumina (ALO8) mixed with CuFe 2 O 4 exhibited the highest DME conversion and hydrogen production with optimum reforming temperature at 350-375 o C. Stable activity for DME hydrolysis was attained over ALO8 with high durability for 25 h.

Copper-iron spinel (CuFe 2 O 4) in cubic phase was prepared via a simple citrate solgel method, and was transformed into tetragonal phase of high crystallinity by calcining in air at 900 °C. Composites of CuFe 2 O 4 spinel and -Al 2 O 3 were investigated for catalytic production of hydrogen from dimethyl ether steam reforming (DME SR). X-ray photoelectron spectroscopy showed Cu 1+-rich surface species (Cu 1+ /Cu 0 = ca. 3/2 with negligible Cu 2+) over the calcined CuFe 2 O 4 subjected to in situ H 2 reduction. The spineloxides with lower content of reducible Cu species possessed higher amount of Cu 1+ species under the reducing atmosphere, corresponding to higher DME SR activity. Copper clusters highly dispersed in the matrix of iron oxides were reduced from the spinel structure, and the strong interaction between them should result in the high activity and durability. The degraded catalysts after DME SR were regenerated by calcining in air in the temperature range of 350 to 800 ºC. Slow deactivation of the composites observed during DME SR at 375 ºC was mainly attributable to non-graphitic carbonaceous species deposited on the catalyst surface.