Selective hydrogenation of 5-hydroxymethylfurfural to 2,5-bis(hydroxymethyl)tetrahydrofuran with NaBH4 over non-thermal plasma treated Ru supported on hierarchical MFI

Abstract

Catalytic hydrogenation of 5-hydroxymethylfurfural (5-HMF) is an intriguing pathway for producing chemical building blocks, including 2,5-bis(hydroxymethyl)furan (BHMF), 2,5-dimethylfuran (DMF), 2,5- bis(hydroxymethyl)tetrahydrofuran (BHMTHF), and 1,2,6-hexanediol (1,2,6-HT). Among them, BHMTHF stands out as an essential substance and serves as a platform molecule to produce several materials, such as polymers, fibers, and foams. However, the conventional process for BHMTHF production has limitations due to a high hydrogen pressure/temperature requirement and a low yield of desired products. In this contribution, we illustrate the selective hydrogenation of 5-HMF to BHMTHF using Ru nanoparticles supported on hierarchical MFI under mild reaction conditions in the presence of NaBH4 as a hydrogen source through a non-thermal plasma pretreatment (NTP) process of catalyst surfaces. By using the NTP approach for catalyst pretreatment, the metallic Ru species are easily obtained, eventually improving the catalytic performances in terms of complete conversion of 5-HMF and complete selectivity to BHMTHF. Additionally, a high BHMTHF yield across multiple catalytic cycles is maintained as long as the metallic Ru species can be preserved. This example highlights the potential of utilizing a Ru-based catalyst in conjunction with the NTP process, providing both an active catalyst and a greener approach for biomass utilization to produce high-valuable products.