Mesoporous SBA-15 supported Ru nanoparticles for effective hydrogenation of ethyl levulinate at room temperature

Mesoporous materials have found wide application as catalyst supports. In this study, we have shown that Ru nanoparticles supported on SBA-15 are highly active toward hydrogenation of biomass-derived ethyl levulinate (EL) even at room temperature. A series of Ru loaded SBA-15 (xRu-SBA-15, x = 1, 3, and 5 wt% Ru) were prepared by a deposition-precipitation method and further reduced with NaBH₄. TEM images suggest that the reduction with NaBH₄ led to the formation of Ru particle with size in range of 1–2 nm. These finely distributed Ru nanoparticles on SBA-15 showed high activity for hydrogenation of C=O group of EL at room temperature and a low H₂ pressure (0.5 MPa), with ethyl hydroxylpentanonate (EHP) selectivity of 97%. Kinetics study showed that the Ru nanoparticles in proper size (2.1 ± 0.1 nm) gave a low apparent activation energy (Ea) about 20 kJ/mol for C=O hydrogenation. Moreover, 3Ru-SBA-15 displayed a good reusability, on which the EL conversion remained stable (− 80%) after five recycles. The produced EHP could be further converted to γ-valerolactone (GVL) over HZMS-5 efficiently upon thermal treatment.