From Sugars to Wheels: The Conversion of Ethanol to 1,3‐Butadiene over Metal‐Promoted Magnesia‐Silicate Catalysts

Abstract 1,3‐Butadiene (1,3‐BD) is a high‐value chemical intermediate used mainly as a monomer for the production of synthetic rubbers. The ability to source 1,3‐BD from biomass is of considerable current interest because it offers the potential to reduce the life‐cycle greenhouse gas (GHG) impact associated with 1,3‐BD production from petroleum‐derived naphtha. Herein, we report the development and investigation of a new catalyst and process for the one‐step conversion of ethanol to 1,3‐BD. The catalyst is prepared by the incipient impregnation of magnesium oxide onto a silica support followed by the deposition of Au nanoparticles by deposition–precipitation. The resulting Au/MgO‐SiO 2 catalyst exhibits a high activity and selectivity to 1,3‐BD and low selectivities to diethyl ether, ethylene, and butenes. Detailed characterization of the catalyst shows that the desirable activity and selectivity of Au/MgO‐SiO 2 are a consequence of a critical balance between the acidic–basic sites associated with a magnesium silicate hydrate phase and the redox properties of the Au nanoparticles. A process for the conversion of ethanol to 1,3‐BD, which uses our catalyst, is proposed and analyzed to determine the life‐cycle GHG impact of the production of this product from biomass‐derived ethanol. We show that 1,3‐BD produced by our process can reduce GHG emissions by as much as 155 % relative to the conventional petroleum‐based production of 1,3‐BD.