Efficient Synthesis Of Styrene From Toluene With Meoh: Via A Ternary Composite Catalyst

To achieve high selectivity of styrene from toluene and methanol, a new strategy, the coupling of methanol dehydrogenation and side-chain alkylation of toluene by ternary composite catalyst combining methanol dehydrogenation, B/SiO2 and CsX components, is proposed. The methanol dehydrogenation component could promote the in-situ formation of formaldehyde (HCHO) intermediate, transferring to B/SiO2 and CsX components. The formation of HCHO over dehydrogenation component is driven by the side-chain alkylation reaction over CsX-B/SiO2 during the coupling reaction. In addition, B/SiO2 is beneficial to stabilize HCHO. When CuO/SiO2 is applied as the dehydrogenation component, the styrene and ethylbenzene yield reaches 31.0 % at a methanol conversion of 60.1 % with the styrene/ethylbenzene molar ratio in products of 3.1 over CsX-CuO/SiO2-B/SiO2. The effective method to prepare a ternary composite catalyst provide helpful guideline for developing a more efficient CsX-based catalyst for conversion of toluene with methanol into styrene in the further.