Abstract
Multioxide catalysts of zinc, copper and titanium with different ratios obtained from layered double hydroxide (LDH) precursors were used in the oxidation of carbon monoxide. The catalysts were characterized by energy-dispersive X-ray spectrometry, X-ray diffraction, thermal analyses (TG, DTG and DTA) and scanning electron microscopy. X-ray diffraction showed different phases of double hydroxide structures. On increasing the percentage of zinc, hydrotalcite structure became the main phase in these samples. SEM images confirmed the presence of layered double hydroxide as plate-like structure. Experimental results indicated a sharp increase in the catalytic activities of the calcined samples towards the oxidation of carbon monoxide at temperatures in the range of 225-275 degrees C. High conversion of carbon monoxide (90 similar to 95%) was achieved at reaction temperature of 275 degrees C by samples having ZnTiO3 as a main phase. These results suggested that hydrotalcite structure of Zn-Ti has a positive catalytic effect towards carbon monoxide oxidation.