Modulating the surface amphipathicity of Ni-Sn composite nanoparticles for efficient upgrading of aqueous ethanol to C6+ alcohols

Aqueous ethanol upgrading has attracted great attention for producing high-valued higher alcohols. Nevertheless, the chain growth for higher alcohol production involving water–oil biphase reaction, is usually limited by the traditional single-phase (hydrophilic or lipophilic) catalyst, leading to poor selectivity of C6+ alcohols. Herein, we demonstrate that modulating the surface amphipathicity of the active Ni-Sn composite nanoparticles by using hybrid carbon shell and TiO2 support significantly boosted its catalytic performance. A high ethanol conversion of 70.6 % and excellent C6+ alcohols selectivity of 57.5 % was achieved. Deep studies show that the enhanced catalytic performance was mainly originated from the facilitated emulsion catalysis by the amphiphilic NiSn@C-TiO2 catalyst, by which the reaction process from aqueous ethanol self-coupling to intermolecular cross-coupling at the oil/water interface was dramatically accelerate. This work developed a novel emulsion catalyst for water/oil biphase interface catalysis, approaching highly efficient production of high-valued higher alcohols from direct upgrading of aqueous ethanol.