Synthesis, characterization and catalytic application of Ni catalysts supported on alumina–zirconia mixed oxides

[摘要] Alumina and alumina–zirconia mixed oxides were compared as supports to prepare nickel catalysts. The oxideswere prepared by the sol–gel method using aluminum tri-sec-butoxide and zirconium (IV) propoxide as precursors, andits physicochemical properties were determined by BET, TGA, DTA, XRD, SEM and TEM. The catalysts of nickel wereobtained by the impregnation of the supports with nickel nitrate (10 wt%) and were heat-treated at 700$^{\circ}$C. The specificarea of the supports and catalysts decreased with the increase in the zirconia content in agreement with the crystallinephase formed. TEM micrographs of nickel catalysts revealed particles in the size range of 10–30 nm. The Ni/Al$_2$O$_3$–ZrO$_2$ catalysts were tested in the steam reforming reaction of ethanol (SRE) at 500$^{\circ}$C, and the obtained results suggest that the differences in catalytic activities depended on the content of ZrO$_2$. The selectivity towards H$_2$ was $\sim$56% for the named catalyst Ni–Al–0.25Zr.

[学科分类] 材料工程

[关键词] Alumina;alumina–zirconia mixed oxides;sol–gel method;nickel catalysts;steam reforming.