Hydrogenation of levulinic acid to γ-valerolactone is a key reaction in the valorization of carbohydrates to renewable fuels and chemicals. State-of-the-art catalysts are based on supported noble metal nanoparticle catalysts. We report the utility of a bimetallic Fe-Re supported on TiO₂ for this reaction. A strong synergy was observed between Fe and Re for the hydrogenation of levulinic acid in water under mild conditions. Fe-Re/TiO₂ shows superior catalytic performance compared to monometallic Fe and Re catalysts at similar metal content. The hydrogenation activity of the bimetallic catalysts increased with Re content. H₂-TPR, XPS, XANES, EXAFS, Mössbauer spectroscopy, TEM, and low-temperature CO IR spectroscopy show that the bimetallic catalysts contain metallic Re nanoparticles covered by FeO_x species and small amounts of a Fe-Re alloy. Under reaction conditions, the partially reduced surface FeO_x species adsorb water and form Brønsted acidic OH groups, which are involved in dehydration of reaction intermediates. Under optimized conditions, nearly full conversion of levulinic acid with a 95 % yield of γ-valerolactone could be achieved at a temperature as low as 180 °C in water at a H₂ pressure of 40 bar.

乙酰丙酸加氢为γ-戊内酯是碳水化合物向可再生燃料和化学物质增值的关键反应。最先进的催化剂是基于负载的贵金属纳米颗粒催化剂。我们报告了在此反应中负载在TiO ₂上的双金属Fe-Re的效用。在温和的条件下，观察到Fe和Re之间有很强的协同作用，可以在水中对乙酰丙酸进行氢化。与单金属的Fe和Re催化剂相比，Fe-Re / TiO ₂在相似的金属含量下显示出优异的催化性能。双金属催化剂的氢化活性随Re含量的增加而增加。高₂-TPR，XPS，XANES，EXAFS，穆斯堡尔光谱，TEM和低温CO IR光谱显示，双金属催化剂包含被FeO _x物种覆盖的金属Re纳米颗粒和少量的Fe-Re合金。在反应条件下，部分还原的表面FeO _x物质吸附水并形成布朗斯台德酸性OH基团，这些基团参与反应中间体的脱水。在优化的条件下，在低至180°C的水中，H ₂压力为40 bar的情况下，可以实现乙酰丙酸的几乎完全转化，并具有95％的γ-戊内酯收率。