Catalytic upgrading biomass-derived ethanol and acetic acid into C4 chemicals

Synthesis of value-added chemicals from biomass is an essential strategy to mitigate the global dependency on fossil resources and achieve the aim of carbon neutrality. Thereinto, ethanol and acetic acid are crucial biomass-derived platform molecules. Recently, catalytic upgrading ethanol and acetic acid into C4 energy-intensive fuels and chemicals via the elongation of carbon backbone has received widespread attention. The primary focus of this review is to systematically describe the recent breakthrough in the conversion of ethanol or acetic acid to C4 chemicals including 1,3-butadiene, n-butenes, isobutene or n-butanol. Special attentions will be given to heterogeneous catalyst design strategies, reaction parameters on the catalytic performance along with the relevant mechanism investigations, as well as their future challenges and opportunities. The present review will provide the detailed insights into the synthesis of C4 chemicals from biomass-derived ethanol and acetic acid and shed a light on the development of highly efficient catalysts.