Highly selective catalytic conversion of phenols to aromatic hydrocarbons on CoS2/MoS2 synthesized using a two step hydrothermal method

Abstract

CoS₂/MoS₂ catalysts were prepared using a two-step hydrothermal procedure for the first time, i.e., MoS₂ was synthesized and then CoS₂ was prepared and deposited on the surface of the MoS₂. The characterization results presented that CoS₂ and MoS₂ are separated in the resultant catalysts and the surface area of CoS₂/MoS₂ was much higher than that of Co–Mo–S prepared using a one step method. In the hydrodeoxygenation (HDO) of p-cresol, the presence of CoS₂ enhanced the conversion, but excessive CoS₂ on the surface of the MoS₂ reduced its activity. With an appropriate amount of CoS₂, the catalyst presented an unprecedented HDO activity and direct deoxygenation (DDO) selectivity: 98% deoxygenation degree with a selectivity of 99% toluene at 250 °C for 1 h. This CoS₂/MoS₂ catalyst also exhibited high DDO activity for other phenolic monomers, which minimized hydrogen consumption and improved the economic efficiency.