Ethyl benzene oxidation under aerobic conditions using cobalt oxide imbedded in nitrogen-doped carbon fiber felt wrapped by spiral TiO2-SiO2

Abstract

Carbon fiber felt (CFF) as a carbonaceous framework has received great attention in catalysis applications. In this work, a novel nanocomposite composed of cobalt oxide micro-sized particles (MPs) incorporated in nitrogen-doped carbon and wrapped by coil-like TiO2-SiO2 layer was fabricated through a co-assembly protocol including MPs implanting, hydrolysis and calcination steps. The structural properties and performance of the prepared Co/N-CFF@TiO2-SiO2 catalyst was evaluated by different techniques. Mechanical, chemical and thermal stabilities of CFF were stepwise improved and the results explain how the N-CFF matrix and strong spiral envelope promoted textural features in the final composite. Moreover, the catalyst exhibited good activity in oxidation of ethyl benzene by molecular oxygen. Under optimized conditions (130 °C, 12 h, 5 mL of ethylbenzene, 20 bar O2 pressure), the ethyl benzene conversion and acetophenone selectivity were 25% and 88%, respectively. The novel Co/N-CFF@TiO2-SiO2 catalyst showed excellent long-term stability over 6 consecutive cycles, which permits to consider it as an ideal platform for application at industrial scales due to its green and bulk nature.