Synergistic RuPt alloy nanoparticles on halloysite nanotubes for efficient decarboxylation of stearic acid to green diesel under mild conditions

The development of cost-effective catalysts for green diesel production from fatty acids is crucial to sustainable energy, yet achieving high efficiency under mild, low-H 2 pressure conditions remains challenging. Natural halloysite nanotubes (HNT), owing to their abundance, low cost, and high metal-loading capability, represent an attractive catalyst support. Herein, RuPt alloy nanoparticles supported on halloysite nanotubes are used for the efficient decarboxylation of stearic acid (SA). Under mild conditions using the in situ H 2 , the optimized Ru 0.7 Pt 1.0 /HNT catalyst exhibits high performance, achieving 87.40% SA conversion, with a C8-C19 alkane selectivity of 90.42%. Meanwhile, the catalyst maintains high catalytic activity over at least three consecutive reaction cycles. Combined experimental results and DFT calculations reveal that the RuPt bimetallic catalyst exhibits a significantly lower activation energy barrier than its monometallic counterparts. This reduction is attributed to electron transfer from Pt to Ru, which lowers the activation energy barrier and accounts for the superior performance. This work establishes a scalable low-noble-metal-loading catalyst design, offering an energy-efficient and sustainable route for green diesel production from waste cooking oils.