(571g) A Novel Catalyst Preparation Method Combining Electrolysis Method and Cathodic Polarization for Highly Stable Cu/Ni/Al2O3 Bi-Functional Catalyst in Steam Reforming of Dimethyl Ether

In this work, a novel monolithic catalyst preparation method combining with electrolysis method and cathodic polarization was firstly proposed and investigated in detail. It was found that the monolithic Cu/Ni/γ-Al2O3/Al bi-functional catalyst prepared by this novel method presented high activity and good stability in the system of steam reforming of dimethyl ether (DME SR) under various conditions. Since traditional methods such as co-precipitation route, sol-gel method and deposition-precipitation method are not suitable for the preparation of plate-type catalyst, conventional impregnation method was selected to support Cu species over γ-Al2O3/Al support. Meanwhile, only small amount of Ni species was required to alleviate the sintering of Cu above 320°C. To reduce the preparation period and fully utilize the outstanding conductivity of Al plate, a novel electrolysis method could be used to support the highly dispersed Ni over Cu/γ-Al2O3/Al catalyst. However, the existence of dense anodic alumina inhibits the application of direct current electrolysis method. Therefore, cathodic polarization (CP) pretreatment was performed to remove the barrier layer between the porous oxide film and Al substrate. The effects of time, voltage and solution for CP on the reduction of barrier layer were studied. It was found that the optimum treatment conditions were 7.5 minutes, 4 volts and 0.5 M KCl solution. Moreover, for dimethyl ether hydrolysis reaction, the catalytic performance of the anodic alumina with CP pretreatment was similar with that of the traditional anodic alumina, indicating that the CP pretreatment had no impact on the γ-Al2O3. On the other hand, Ni was highly dispersed on the surface of Cu/γ-Al2O3/Al catalyst pretreated with CP. Finally, the durability test of CP-Cu/Ni/γ-Al2O3/Al catalyst was carried out and the results showed that it exhibited excellent stability at 400°C for 40h, with 100% DME conversion and 70% H2 yield, indicating its good application prospect in the domestic fuel cell system.