Anion-Induced Surface Curvature for Modulating Electronic Structures to Enhance Aqueous-Phase C–C Coupling toward Biofuel Precursors

The direct synthesis of bioaviation fuel precursors from furfural (FF) aqueous solutions represents a promising and more sustainable approach. Herein, we report MgAlSnO mixed oxides derived from MgAlSn-LDH intercalated with various interlayer anions, exhibiting favorable activity for the aqueous C–C coupling of FF and methyl isobutyl ketone (MIBK). MgAlSnO-CA demonstrates optimal resistance to water poisoning, achieving 96% conversion of FF in high-water-content systems (MH2O/FF = 7). Furthermore, the excellent catalytic activity of MgAlSnO-CA in various aqueous-phase C–C couplings of biomass-derived molecules confirms broad applicability. In situ DRIFTS studies and contact angle measurements reveal that water dissociation enables the catalyst to exhibit superior resistance to water poisoning. Poisoning experiments confirmed that the acidic sites on the catalyst served as the active sites for water dissociation. DFT calculations reveal that the charge density of Sn influences the strength of the p-p orbital, which plays a decisive role in determining the water dissociation rate and water-poisoning resistance. This study provides guidance for the direct resource utilization of FF aqueous solutions and suggests a novel strategy to mitigate the water poisoning of metal oxides.