Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

IntroductionHYDROGEN PRODUCTION BY STEAM REFORMING OFDIMETHYL ETHER OVER Cu-Zn/CeO 2 -ZrO 2 CATALYTICMONOLITHSCristian Ledesma, Jordi LlorcaInstitut de Tècniques Energètiques, Universitat Politècnica de CatalunyaAv. Diagonal 647, Ed. ETSEIB, 08028 Barcelona, SPAINFax : (0034)934017149, E-mail : jordi.llorca@upc.eduOP-V-11Hydrogen and fuel cells are attracting much attention as potential devices for energytransportation and transformation. Steam reforming and oxidative steam reforming of naturalgas and other hydrocarbons as well as alcohols as a route for producing hydrogen in a varietyof environments have been addressed extensively in the last decades. Dimethyl ether (DME)has recently become a potential fuel for hydrogen production because provides a highhydrogen to carbon ratio, has a high energy density, and can be easily handled, stored, andtransported [1-4] .Steam reforming of DME comprises two consecutive, moderately endothermic reactions:DME hydrolysis and methanol (MeOH) steam reforming. The overall reaction is (1) [4] :(CH 3 ) 2 O + 3 H 2 O 6 H 2 + 2 CO 2 ΔHº=135 kJ mol –1 (1)The hydrolysis reaction is known to take place actively over acidic catalysts. Since DMEhydrolysis provides low equilibrium conversion, an active catalyst to effectively reformmethanol is also the key for DME steam reforming. In general, steam reforming of MeOHproceeds over Cu-, Pt- or Pd-based catalysts [4] . As a consequence, catalyst formulationscontaining both acidic and metal sites are thus preferred.In this work, DME steam reforming has been performed over several Cu-Zn/CeO 2 -ZrO 2catalysts, which have been used for coating cordierite monolithic structures for practicalapplication [5] .Catalysts preparationCordierite monoliths were first coated with 10% w/w of ZrO 2 , CeO 2 and Ce 0.5 Zr 0.5 O 2supports, using zirconium oxychloride and cerium trichloride as precursors. Monoliths weredried under continuous rotation at 373 K for 2 h and calcined in air at 773 K for 2 h. Cu, orZn, or a mixture of Cu and Zn were then added to each support by incipient wetnessimpregnation using copper nitrate and zinc nitrate as precursors. The total metal loading wasca. 10% w/w with respect to the support. The resulting catalytic monoliths were dried undercontinuous rotation at 373 K for 2 h and calcined in air at 773 K for 5 h.187