LAUSR

Ethanol is a considerable platform molecule in biomass conversion, which could be acquired in quantity through acetone-butanol-ethanol (ABE) fermentation. People have been working on the upgrading of ethanol to value added chemicals for decades. In the meantime, 1-butanol and a series of value added products have been selectively generated through C-C bond coupling. In this mini-review, we focus on the recent advances in selective C-C bond formation over balanced Lewis acid-base catalysts such as modified metal oxide, mixed metal oxide, hydroxyapatite and zeolite confined transition metal oxide catalysts. Among them, Pd-MgAlOx and Sr-based hydroxyapatite exhibit >70% 1-butanol selectivity, while ZnxZryOz and Ta-SiBEA zeolite achieve >80% of isobutene and butadiene selectivity respectively. The mechanism and reaction pathway of C-C bond formation in each reaction system are described in detail. The correlation between C-C bond coupling and the acidity/basicity of the Lewis acid-base pairs from the surface of the catalysts are also discussed.