Boosting C6-12 alcohols yield from ethanol upgrading by balancing dehydrogenation/hydrogenation and C-C coupling rates
Abstract
The conversion of biomass-derived ethanol into C6-12 alcohols offers a sustainable route for producing fine chemicals such as plasticizers and surfactants, but is hindered by challenges in enhancing and matching complex reaction rates that involve dehydrogenation/hydrogenation and C-C coupling. Herein, we design a hydroxyapatite-supported multifunctional catalyst system (Cu/HAP+Y/HAP) that efficiently converts ethanol into C6-12 alcohols, achieving selectivity of 71.8% and yield of 38.1% at 250 ℃, which is superior to that of reported catalysts in the literature. The introduction of Y3+ increased the C-C coupling rate to 26.9 mmol·gCat.-1·h-1 on HAP, matching the Cu0 enhanced hydrogenation/dehydrogenation rates of HAP. Specifically, by combining physical structure and chemical state analysis, we reveal that the active hydrogen generated at Cu0 sites migrates to HAP and Y3+ sites, thereby promoting surface-mediated hydrogenation of the C=C bond in butenal to butanal. The resulting butanal is subsequently generated into long-chain aldehydes by self-coupling or cross-coupling at the Y3+ site and the HAP basic site, and finally hydrogenated to form C6-12 alcohols. This study develops an efficient strategy for the targeted conversion and valorization of ethanol by precisely matching the rates of dehydrogenation/hydrogenation, coupling through catalytic system engineering, providing a valuable reference for catalyst design in high-value chemical conversion.
