Catalytic and electrocatalytic oxidation of ethanol over a La0.6Sr0.4Co0.8Fe0.2O3 perovskite-type catalyst

The catalytic and electrocatalytic behavior of the perovskite-type La0.6Sr0.4Co0.8Fe0.2O3 catalyst was investigated during ethanol oxidation. Experiments were carried out at atmospheric pressure in a fully yttria-stabilized zirconia (YSZ) continuously stirred tank reactor (CSTR) in the temperature range between 300 and 750°C and fuel-rich reactant mixtures (PO2=2 kPa, Pethanol=13.5 kPa). It was found that oxygen–nitrogen streams saturated with ethanol (at room temperature and atmospheric pressure) lead mainly to the formation of formaldehyde and acetaldehyde. For the aforementioned reaction conditions, gas-phase oxidation becomes predominant at temperatures higher than 650°C and in combination with heterogeneous phenomena leads to 100% ethanol conversion and high acetaldehyde yields (75%) at about 750°C. The electrochemical supply of oxygen anions mainly affects the formation rates of CO and CO2. Due to the high operating temperatures, direct electrocatalysis and homogeneous reactions, more than NEMCA (Λmax=3), affect the overall kinetic behavior.