Protective desilication of beta zeolite: A mechanism study and its application in ethanol-acetaldehyde to 1,3-butadiene

The conversion of bioethanol to 1,3-butadiene (ETB) is expected to be one of the most promising routes to alternate the petroleum route. However, the preparation of hierarchical beta zeolite to serve as the catalyst support is still challenging. In this work, hierarchical beta zeolite was prepared through protective desilication by quaternary ammonium hydroxide (TAAOH), and Zr-beta zeolite was prepared using the hierarchical beta zeolite by dealumination-metallization strategy for ETB reaction. The mechanism of protective desilication was clarified by some control experiments. The protection of TAA+ coexists with OH- attacking and they act in different treating stage, and there lies the best treatment concentration regarding to the mesoporous formation in beta zeolite. By adjusting the length of TAAOH alkyl chain, the mesoporosity of beta zeolite was tuned successfully. The catalytic activity of Zr-beta zeolite was enhanced by the generation of mesoporosity and better capability of coke was achieved which mitigated the deactivation.

Automated summary

Hierarchical beta zeolite was prepared through protective desilication with quaternary ammonium hydroxide, and Zr-beta zeolite was prepared using the hierarchical beta zeolite. The mesoporosity of beta zeolite was successfully tuned by adjusting the length of TAAOH alkyl chain, leading to enhanced catalytic activity of Zr-beta zeolite.