Noble-metal high-entropy-alloy tuning the products of electrocatalytic 5-hydroxymethylfurfural oxidation

Abstract

Noble-metal high-entropy-alloy nanoparticles (HEA NPs) have been synthesized via the co-reduction of noble-metal precursors in triethylene glycol and show activity in the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to valuable chemicals. The PtRhPdIr quaternary alloy initiates the oxidation via attacking either the hydroxyl or formyl group parallelly, forming 2,5-diformyl furan (DFF) and 5-hydroxymethyl-2-furan carboxylic acid (HMFCA), respectively, either of which can be oxidized further to formyl-furan carboxylic acid (FFCA) and 2,5-furandicarboxylic acid (FDCA). The addition of either Au or Ru to form quinary HEA NPs facilitates the hydroxyl group oxidation to generate the intermediate DFF. If both Au and Ru are added to form senary PtRhPdIrAuRu HEA NPs, the initial oxidation of the formyl group in HMF is facilitated to generate the intermediate HMFCA. The results show that the composition of the HEA NPs significantly affects the product selectivity by regulating the pathways.