Porous dendritic BiSn electrocatalysts for hydrogenation of 5-hydroxymethylfurfural

The electrocatalytic hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)furan (BHMF) is an alternative to conventional heterogeneous catalysis with H₂ at high temperatures and pressures. Although Ag is the most representative electrocatalyst, it works only under limited conditions. This study synthesizes highly porous dendritic Bi, Sn, and BiSn electrocatalysts using an in situ generated hydrogen bubble template. Density functional theory computations on the adsorption energy and elementary hydrogenation reaction steps of HMF predict the superiority of Bi to Sn and the intermediate behavior of BiSn between Bi and Sn. The dendritic BiSn catalyst generates a current density of ∼144 mA cm⁻² at a faradaic efficiency (FE) of ∼100% for BHMF production at pH ∼ 7 (corresponding to the BHMF production rate of ∼2.7 mmol h⁻¹ cm⁻²) in prolonged electrolysis. Considering the material cost (<5% of Ag price) and quick synthesis (<40 s), dendritic BiSn should be a promising candidate for HMF hydrogenation.