Configuration of coupling methanol steam reforming over Cu-based catalyst in a synthetic palladium membrane for one-step high purity hydrogen production

Abstract

Methanol steam reforming coupled with an efficient hydrogen purification technology to produce high purity hydrogen that feeds for hydrogen fuel cells is an attractive approach to realizing distributed power generation. However, the harmony of catalytic reforming and hydrogen separation with respect to thermodynamics is still an issue. In this work, in order to construct an integrated methanol steam reforming (MSR) reactor for high purity hydrogen production, CuCe/Al2O3 was synthesized by a hydrothermal-impregnated method and a Pd membrane supported by a porous ceramic using the electroless plating method. The results revealed that the catalytic activity and high temperature stability for methanol steam reforming were evidently improved by tuning the copper dispersion, porous structure and the crystal phase. The coupling range with palladium membrane operating temperature was widened. CuCe/Al2O3 presented an excellent stability with a better carbon deposition resistance for the long-term tests than Cu/Al2O3, which exhibited 836.68 μmol/gcat. min of H2 production with low carbon deposition (3.38 wt%) and lower CO emission (0.48 vol%). A 10 μm thick Pd membrane that was deposited on the ceramic support displayed dense and even surface morphology. The effect of palladium membrane structure on hydrogen separation was analyzed. In addition, the influence of temperature on coupling was discussed. Ultimately, high purity of H2 (99.36 vol%) was achieved at 400 °C by integrating the Pd membrane reactor with methanol steam reforming. The internal temperature distribution of the reactor and the effects of feeding conditions were also investigated. This work might offer certain reference for the development of the future distributed integrated hydrogen power generation system, especially in the application of electric vehicles and on-site electricity.