Base-free Oxidative Esterification of HMF over AuPd/nNiO-TiO2. When Alloying Effects and Metal-support Interactions Converge in Producing Effective and Stable Catalysts

Furan-2,5-dimethylcarboxylate (FDMC), along with ethylene glycol (EG), is the key monomer to produce (poly-(ethylene-furanoate) (PEF). Noble metal-based catalysts can convert hydroxymethyl furfural (HMF) to FDMC in methanol through liquid phase catalytic oxidative esterification. In this work, the catalytic performance of Au, Pd and AuPd NPs supported on nanosized nickel oxide (nNiO) have been evaluated under base-free conditions at 90 degrees C and 3 bar O-2. Synergistic effects between Au and Pd imparted high activity and higher yield to FDMC compared to the monometallic counterparts. The role of support was also investigated by depositing AuPd NPs on TiO2 and nNiO-TiO2. Remarkable yield to FDMC (85 % after 8 h) and high stability were observed over AuPd/ nNiO-TiO2 catalyst. This peculiar catalytic behavior could be imputed to the formation of trimetallic AuPdNi particles offering highly active interfacial sites.

Automated summary

This study evaluated the catalytic performance of Au, Pd, and AuPd nanoparticles supported on nanosized nickel oxide (nNiO) for the production of Furan-2,5-dimethylcarboxylate (FDMC). Synergistic effects between Au and Pd were found, leading to higher yield of FDMC. The AuPd/nNiO-TiO2 catalyst exhibited remarkable catalytic activity and stability, attributed to the highly active interfacial sites formed by trimetallic AuPdNi particles.