EFFECTS OF CALCINATIONS TEMPERATURE ON THE STRUCTURE OF CuO-ZrO₂ NANOPARTICLES

Nano sized copper oxide-zirconia particles were prepared by using a sol-gel technique. The phase change with the calcinations temperature was also investigated for the sample containing 30 wt% copper. It was found that the calcinations temperature strongly influenced the interaction between the active species and support and hence the structure and catalytic performance. Low calcinations temperature yielded poorly crystallized catalysts and favored the formation of a Cu(OH)₂ and Zr(OH)₄ like structure. The results show that cubic ZrO₂ and copper oxide were present below calcinations at 400°C, and cubic ZrO₂ with some amount of monoclinic ZrO₂ and tetragonal ZrO₂, as well as copper oxide, formed after calcinations at 500°C. However, below heating at 500°C, amorphous compounds were obtained; suggesting that 500°C could be a phase transition point. The incorporation of copper in the ZrO₂ lattice resulted in a loss of order in the ZrO₂ structure when calcined at 500°C, with a further increase in the calcinations temperature leading to the phase change. In this work, the latest results on nano crystalline CuO-ZrO₂ as the catalyst for hydrogen synthesis from methanol is reported. The effect of calcinations temperature on the nanoparticle structure of catalyst is focused.