Electrocatalytic synthesis of bio-based branched alkanes towards sustainable aviation fuel.

Abstract

Branched C8-C16 alkanes are highly desirable sustainable aviation fuel (SAF) components, as they confer low freezing points and favorable combustion properties. Currently, these alkanes are produced predominantly via the hydroprocessed esters and fatty acids (HEFA) pathway, which requires harsh hydrogenation and hydroisomerization conditions that often promote cracking and carbon loss, resulting in high energy consumption and limited yields (20-40 %). Here, we present a mild electrocatalytic strategy that converts bio-derived C2-C4 fatty acids and methyl acrylate into C8-C16 branched alkanes. Using a platinum electrode at ambient pressure and ice-bath temperature, this strategy integrates radical addition, hydrolysis, and decarboxylative coupling in a tandem sequence to achieve efficient carbon-chain growth from short-chain feedstocks. In contrast to HEFA, the process is driven by electrochemical radical generation and selective C-C bond formation rather than hydrogenation, thereby avoiding external H2 and suppressing the cracking reactions. As a result, the target branched alkanes are obtained in yields of up to 72.5 %, while the mild operating conditions also substantially reduce both energy input and carbon footprint. This work establishes a mild electrosynthetic paradigm for upgrading bio-based chemicals into SAF-range branched alkanes, thereby offering a complement to mainstream HEFA technology.