Synthesis of γ-Valerolactone from Levulinic Acid with Co/NC, and from Furfural via Cascade Reaction Using Co/NC and H-Beta

gamma-Valerolactone (GVL) has transpired as an ecofriendly solvent, a promising fuel additive, and a precursor to valuable chemicals. The study explores an approach to GVL synthesis by employing non-noble metals in contrast to conventional methods involving noble metals. The selective hydrogenation of levulinic acid (LA) and levulinate esters offers a pathway to GVL production, while the direct transformation from furfural (FA) enhances its potential. The study focuses on 3d transition metal-based N-doped carbon catalysts, highlighting Co/NC as the most effective catalyst for LA to GVL hydrogenation, yielding similar to 100% GVL. The catalyst was also employed in a one-pot, three-step cascade reaction: FA hydrogenation to furfuryl alcohol (FOL) was performed using 10% Co/NC, ethanolysis of FOL to ethyl levulinate (EL) was facilitated by H-beta, and EL hydrogenation to GVL was performed using 10% Co/NC. Each step was optimized independently. The cascade reaction was executed at 140 degrees C for 12 h through a comprehensive approach, achieving a noteworthy 92.1% GVL yield from FA, which was further upcycled to the gram scale, offering 86% of the final GVL yield. The catalyst characterization, catalytic activity data, and control experiments culminate in the proposed LA to GVL transformation mechanisms and the one-pot, three-step cascade FA to GVL conversion. The research significantly contributes to advancing sustainable GVL production and its multifaceted applications.