USE OF CERAMIC MEMBRANES COATED WITH CuO AND ZrO2 IN THE OXIDATION OF CO TO CO2
This study evaluated the use of coated ceramic membranes (CCMs) with copper and zirconium oxides in the oxidation of carbon monoxide (CO) to carbon dioxide (CO2). The ceramic membranes were prepared though the impregnation of polymeric matrices with slurries, which were formulated with different proportions of clay minerals from Ecuador (clay, feldspar, and quartz), the impregnated matrices were sintered at 1100, 1135, and 1170 °C. Different membranes were obtained, and their resistance to compression and porosity was evaluated in order to select the formulation and temperature that allowed to maximize these properties. Thus, it was identified that the formulation of 66.5% clay, 20% feldspar, 13.5% quartz, and a temperature of 1135 °C allowed obtaining membranes with values of porosity of the order of 91 ± 0.5% and resistance to compression of 0.098 ± 0.02 MPa. The selected membranes were coated by dip-coating with different suspensions of CuO a/o ZrO2. The CCMs were heated to 500 °C, then their reducibility was evaluated by temperature-programmed reduction with CO (CO-TPR) in order to determine the percentage of coating that allows the production of CO2. Finally, the CO conversion was analyzed. It was determined that the CCMs with a load of 7.1 ± 0.6% CuO produced 16.02 cm3 of CO2 /gsample at 236.2 °C and allowed conversion of 100% of CO at 250 °C, while the CCMs with a load of 5.3 ± 0.4% CuO and 1.9 ± 0.2% ZrO2 produced 9.2 cm3 of CO2 /gsample at 230.4 °C and obtained a conversion of 100% of CO at 250 °C. Therefore, it is considered that the oxidation of CO is linked to the presence of CuO.