N 2 O-assisted methanol selective oxidation to formaldehyde on cobalt oxide catalysts derived from layered double hydroxides

Abstract Cobalt-magnesium-aluminum oxides derived from layered double hydroxides were used as catalysts for the conversion of methanol to formaldehyde in the presence of nitrous oxide. The catalysts were characterized by XRD, FTIR, UV–vis DRS, TPR-H 2 , NH 3 - and CO 2 -TPD and N 2 adsorption. 100% methanol conversion and 91% selectivity to formaldehyde were simultaneously obtained with 100% N 2 O conversion at 440 °C over a Co,Mg,Al-mixed oxide catalyst. Higher hydrogen yields and lower CO and CO 2 yields were obtained than when air was used as oxidizing agent, under the same conditions. These findings suggest that the reaction occurs on a combination of redox and basic catalytic sites.