Highly dispersed sol–gel synthesized Cu–ZrO2 materials as catalysts for oxidative steam reforming of methanol

New nanodispersed Cu–ZrO2 systems (containing 0 and 8.3 mol% Cu) were synthesized by sol–gel method. Homogeneous gels were prepared starting from Zr propoxide and Cu(NO3)2·2.5H2O. The materials were characterized by XRD, TG/DTA, N2 adsorption, TPR techniques and N2O surface oxidation. In the Cu-containing material part of Cu2+ ions were incorporated into the zirconia lattice and strongly influenced the crystallisation behaviour of zirconia matrix. After treatment at 450–600 °C, the materials contained ZrO2 nanocrystals of the tetragonal polymorph. The samples heat treated up to 450 °C showed high surface areas in the range 140–180 m2/g. Copper oxide species with different reducibility were detected by TPR measurements. The H2 reduction treatments gave rise to metallic copper with very high dispersion. The catalysts showed high activity for the oxidative steam reforming of methanol. A noticeable activity was observed also with the not pre-reduced catalyst, although a previous reduction in H2 led to a higher selectivity and H2 production.

Graphical abstractA novel one-pot sol–gel route allows to obtain Cu–ZrO2 with high surface areas (140–180 m2 g−1) and extraordinary dispersion of metallic Cu after reduction with H2. Cu(II) dissolved into ZrO2 stabilizes the tetragonal form. Not pre-reduced Cu–ZrO2 shows OSRM activity similar to that of Cu–ZrO2 pre-reduced at 300 °C. Zirconia contributes to the catalytic activity producing mainly (CH3)2O and CH2O. (For interpretation of the references to color in this artwork, the reader is referred to the web version of the article.)Figure optionsDownload full-size imageDownload high-quality image (95 K)Download as PowerPoint slide