Probing the promotional roles of lanthanum in physicochemical properties and performance of ZnZr/Si-beta catalyst for direct conversion of aqueous ethanol to butadiene

Here, the efficient synthesis of butadiene from aqueous ethanol was achieved over a series of x%LaZnZr/Si-beta multifunctional catalysts prepared by wet impregnation method. La species played a crucial role in improving the physicochemical properties and catalytic performance of the ZnZr/Si-beta catalyst. The structure and physico-chemical properties of the synthesized catalysts were analyzed by multiple characterization technique. The characterization results revealed that the introduction of La species into ZnZr/Si-beta catalyst created a new La -O-Si bond, and rationally modified the acid-base properties. The La species substantially improved the main reaction of aldol condensation and inhibited the ethanol dehydration, as demonstrated by ethanol-TPD and TPSR studies. In addition, the adsorption capacity of water vapor was remarkably suppressed. A remarkable butadiene selectivity of 60.6 % and ethanol conversion of 83.4 % were achieved on the 5 %LaZnZr/Si-beta catalyst. This enhancement of butadiene selectivity and catalytic activity is very helpful for the development of novel efficient multifunctional catalysts for the direct synthesis butadiene from aqueous ethanol.

Automated summary

The efficient synthesis of butadiene from aqueous ethanol was achieved over a series of x%LaZnZr/Si-beta multifunctional catalysts prepared by wet impregnation method. The introduction of La species improved the physicochemical properties and catalytic performance of the ZnZr/Si-beta catalyst. The La species enhanced the main reaction of aldol condensation and inhibited ethanol dehydration, resulting in higher butadiene selectivity and ethanol conversion.