A cheap, scalable and efficient nickel catalyst on nitrogen-doped carbon for the aqueous-phase hydrogenation of biomass-derived compounds in flow system.

Monometallic Pt catalysts supported on mesoporous (MP) ZrO 2 were prepared and utilized as catalysts in the aqueous-phase upgrading of lignocellulosic biomass-derived levulinic acid (LA), with formic acid (FA) serving as a sustainable reducing agent. Among the studied catalysts, 1.6Pt/mesoporous ZrO 2 showed the highest LA conversion (97%) and a γ-valerolactone (GVL) yield (90%) at 513 K after 24 h of reaction was achieved. This high LA conversion and GVL yield obtained can be attributed to the high specific surface area (204 m 2 g −1 ) and density of acid sites (136 μmol g −1 ) and Pt dispersion (37%). Furthermore, this catalyst exhibits high stability after 96 h of reaction time, that is, four catalytic repetitions, with a GVL yield above 60% and no change in the crystal structure of the support. A high reaction temperature (533 K) tends to shift the reaction equilibrium from GVL to pentanoic acid which is formed with a yield of 22% after 24 h. Even after increasing the complexity of the model mixture by adding vanillin (V) as a lignin-derived model compound to the aqueous solution of LA and FA, the catalyst remained stable and the hydrogenation of LA and V succeeded, resulting in 43% of GVL and 65% of 2-methoxy-4-methylphenol after 24 h at 513 K.

The continuous flow synthesis of p-Xylene (pXL) via Diels-Alder cycloaddition of lignocellulosic biomass-derivable 2,5-dimethylfuran (DMF) and acrylic acid (AA) was performed over different type of zeolites, i.e. Beta, ZSM-5 and...

The need for more sustainable products and processes has led to the use of new methodologies with low carbon footprints. In this work, an efficient tandem process is demonstrated for the liquid‐phase catalytic upgrading of lignocellulosic biomass‐derived γ‐valerolactone (GVL) with trioxane (Tx) to α‐methylene‐γ‐valerolactone (MeGVL) in flow system using Cs‐loaded hierarchical beta zeolites. The introduction of mesopores along with the presence of basic sites of mild strength leads to MeGVL productivity 20 times higher than with the bulk beta zeolite, reaching 0.325 mmol min−1 gcat−1 for the best‐performing catalyst, the highest value reported so far. This catalyst proves stable upon reuse in consecutive cycles, which is ascribed to the partial depletion of the basic sites. The obtained MeGVL is subjected to visible‐light‐induced polymerization, resulting in a final material with similar properties to the widely used poly(methyl) methacrylate.