Ru‑supported mesoporous melamine polymers as efficient catalysts for selective hydrogenation of aqueous 5‑hydroxymethylfurfural to 2,5‑bis‑(hydroxymethyl)furan

Abstract

A Ru-decorated porous melamine polymer is found to be an active catalyst upon selective hydrogenation of aqueous 5-hydroxymethylfurfural to 2,5-bis-(hydroxymethyl)furan (yield > 99%) under mild (20 bar H2,30–90 °C), base/additive free conditions. Owing to its porous structure and unique surface chemistry presenting abundant weakly basic N-sites (amine and triazine), the polymeric catalyst could outperform various benchmark Ru catalysts (viz. Ru/AC, Ru/SBA-15, Ru/Nb2O5, Ru/ NbOPO4, Ru/NC, and Ru/g-C3N4) in terms of activity and desired product selectivity. The catalytic material was also found to be reusable and maintained good performance during multiple recycles under kinetic regime in batch mode. Furthermore, the polymeric catalyst also showed good performance for selective HMF hydrogenation under intensified conditions in a fixed-bed reactor achieving constant BHMF yield during 20-h steady-state operation under relatively mild conditions (70 °C,20 bar, WHSV 0.2 h−1).