A highly efficient Fe/Beta catalyst for the liquid-phase oxidation of naphthalene: The influence of Fe species and zeolite acidity

Fe/Beta catalysts with various Fe species and acidity were prepared by impregnation (im), ion-exchange (ex) and hydrothermal (hy) method. The properties as well as their catalytic activities were compared by various physicochemical techniques and liquid-phase oxidation of naphthalene (NAP) in detail. Among the three Fe/Beta catalysts, as high as 78% content of isolated Fe3+ species were incorporated into Beta zeolites by hydrothermal method. The isolated Fe3+ species of Fe/Beta(100)-hy distributed homogeneously through the Beta zeolites while the Fe species of Fe/Beta(100)-im and Fe/Beta(100)-ex distributed preferred on the surface of Beta zeolites. The total acid density increased after the incorporation of Fe species by hydrothermal method. Fe/Beta(100)-hy with the highest content of isolated Fe3+ species and enhanced acid density showed the highest catalytic activity.