One-pot synthesis of high-carbon bio-alcohols from aqueous ethanol upgrading over water-tolerance NiSn@C catalyst

Abstract Considering clean energy demands and CO2 neutralization, the production of high energy density biofuels for low-carbon transportation by directly upgrading of biomass fermentation bio-ethanol is of great significance and interesting. Herein, we report an efficient strategy of one-pot synthesize higher carbon bio-alcohols by hydrothermal coupling of aqueous ethanol. The non-precious NiSn@C heterogeneous catalyst with excellent water-tolerance ability and efficient activity was fabricated. Based on this, the aqueous ethanol (water content of 50 wt%) was directly converted into phase-separable higher carbon bio-alcohols with about 47% ethanol conversion and 36% C4+ bio-alcohol yield. The correlation between catalyst chemical states and the step-growth carbon distribution of higher alcohols were also discussed. This work provides guidance for the direct upgrading of water-containing bio-ethanol to desired biofuel components, thus improving the economic feasibility by reducing energy-intensive purifications and distillations.