Biomass-derived Levulinic Acid Research Articles

Nanocavity in hollow sandwiched catalysts as substrate regulator for boosting hydrodeoxygenation of biomass-derived carbonyl compounds.

Hydrodeoxygenation of oxygen-rich molecules toward hydrocarbons is attractive yet challenging in the sustainable biomass upgrading. The typical supported metal catalysts often display unstable catalytic performances owing to the migration and aggregation of metal nanoparticles (NPs) into large sizes under harsh conditions. Here, we develop a crystal growth and post-synthetic etching method to construct hollow chromium terephthalate MIL-101 (named as HoMIL-101) with one layer of sandwiched Ru NPs as robust catalysts. Impressively, HoMIL-101@Ru@MIL-101 exhibits the excellent activity and stability for hydrodeoxygenation of biomass-derived levulinic acid to gamma-valerolactone under 50°C and 1-megapascal H2, and its activity is about six times of solid sandwich counterparts, outperforming the state-of-the-art heterogeneous catalysts. Control experiments and theoretical simulation clearly indicate that the enrichment of levulinic acid and H2 by nanocavity as substrate regulator enables self-regulating the backwash of both substrates toward Ru NPs sandwiched in MIL-101 shells for promoting reaction with respect to solid counterparts, thus leading to the substantially enhanced performance.

Yolk-shell electron-rich Ru@hollow pyridinic-N-doped carbon nanospheres with tunable shell thickness and ultrahigh surface area for biomass-derived levulinic acid hydrogenation under mild conditions

Aiming to efficiently upgrade renewable biomass-derived levulinic acid (LA) into γ-valerolactone (GVL), we have devised yolk-shell electron-rich Ru@hollow pyridinic-N-doped carbon nanospheres, featuring a tunable shell thickness (20−70 nm) and an ultrahigh surface area (4016 m2 g−1). Experimental and theoretical investigations reveal that the strategic formation of the yolk-shell structure and appropriate thinning of the carbon shell facilitate the generation of electron-rich Ru0 and a positive shift of the d-band center towards the Fermi level by increasing surface pyridinic-N species. These modifications suitably intensify Ru0−H interaction, promote reactant adsorption, stimulate electron transfer between active H and the CO group of LA, and ultimately reduce apparent activation energy. Consequently, a high LA turnover frequency (18733.4 h−1 at 30 °C) and GVL selectivity (99.9%), alongside excellent stability up to eight cycles, are achieved, markedly outperforming externally-supported analogues. These findings afford valuable insights into designing yolk-shell nanostructures for biomass upgrading through microenvironment engineering.

Polymer supported Ru nanoparticles for highly selective hydrogenation of biomass-derived levulinic acid to γ-valerolactone: Does the polymer affect the catalytic performance?

Polymer supported Ru nanoparticles for highly selective hydrogenation of biomass-derived levulinic acid to γ-valerolactone: Does the polymer affect the catalytic performance?

Selective production of γ-valerolactone from biomass-derived levulinic acid over a Ni/CMK-3 catalyst

The conversion of levulinic acid (LA) into γ-valerolactone (GVL) is a critical reaction for upgrading biomass into high value-added chemicals.

Catalytic production of 1,4-pentanediol from lignocellulosic biomass

This review gives a broad overview of the conversion of biomass-derived levulinic acid (LA) and furfural into valuable 1,4-pentanediol (1,4-PDO), which is a degradable polyester monomer.

Ni-Cu and Ni-Co-Modified Fly Ash Zeolite Catalysts for Hydrodeoxygenation of Levulinic Acid to γ-Valerolactone.

Monometallic (Ni, Co, Cu) and bimetallic (Ni-Co, Ni-Cu) 10-20 wt.% metal containing catalysts supported on fly ash zeolite were prepared by post-synthesis impregnation method. The catalysts were characterized by X-ray powder diffraction, N2 physisorption, XPS and H2-TPR methods. Finely dispersed metal oxides and mixed oxides were detected after the decomposition of the impregnating salt on the relevant zeolite support. Via reduction intermetallic, NiCo and NiCu phases were identified in the bimetallic catalysts. The catalysts were studied in hydrodeoxygenation of lignocellulosic biomass-derived levulinic acid to γ-valerolactone (GVL) in a batch system by water as a solvent. Bimetallic, 10 wt.% Ni, and 10 wt.% Cu or Co containing fly ash zeolite catalysts showed higher catalytic activity than monometallic ones. Their selectivity to GVL reached 70-85% at about 100% conversion. The hydrogenation activity of catalysts was found to be stronger compared to their hydration ability; therefore, the reaction proceeds through formation of 4-hydroxy pentanoic acid as the only intermediate compound.

Room temperature synthesis of N-substituted pyrrolidone from levulinic acid and nitrobenzene via a tandem hydrogenation and reductive amination process

N-substituted pyrrolidone is one type of organic small molecules with high added values. The synthesis of N-substituted pyrrolidone via a tandem hydrogenation and reductive amination of biomass-derived levulinic acid (LA) with nitroarenes is an attractive route, but has rarely been reported, especially at room temperature. Herein, various Pt-based catalysts were used for the one-pot hydrogenation/reductive amination of LA with nitrobenzene and 96.0% yield of 5-methyl-N-phenyl-2-pyrrolidone (MNPP) was achieved over 0.5Pt/Nb2O5 at 30 °C, 24 h. Deep investigations demonstrated that the strongest ability of Nb2O5 to activate CO bond in LA and the hydrogenation ability of small size of Pt particles were the key factors to realize room temperature synthesis over 0.5Pt/Nb2O5. This Pt/Nb2O5 catalyst was reused 5 runs without obvious deactivation and it can be extended to various N-substituted pyrrolidone’s synthesis directly from LA and different nitroarenes at room temperature. This work would be helpful for designing more efficient reductive amination catalysts.

Insights into the structure–activity relationship in aqueous-phase hydrogenation of levulinic acid to 1,4-pentanediol over bimetallic Ru-Re/C catalysts

Hydrogenation of biomass-derived levulinic acid (LA) to 1,4-pentanediol (PDO) is a sustainable route to replace petroleum-derived polyols. Although the combination of ruthenium (Ru), a hydrogenating metal, and rhenium (Re), an oxophilic promoter, results in high activity for PDO production, the synergistic effect between Ru and Re and the effect of carbon support are not well understood. In this study, the factors determining the catalytic activity and selectivity of carbon-supported RuRe for PDO production were investigated. Bimetallic RuRe nanoparticles with various atomic ratios and monometallic Ru and Re were supported on various carbon materials with different surface properties such as activated carbon (AC), carbon black (CB), mesoporous carbon (CMK-3), carbon nanofiber (CNF) and their reaction kinetics were compared. The structural and physicochemical properties of the catalysts were characterized using X-ray diffraction, temperature-programmed reduction, N2-physisorption, transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic activity and PDO selectivity were correlated with the metal particle size, pore structure, and surface oxygen functionalities, in which the smaller RuRe nanoparticles with a Re-enriched surface supported on carbon with a larger pore size exhibited a higher PDO production rate. Among the catalysts, RuRe supported on CB exhibited the highest PDO selectivity (∼75 %) at 130 °C and 50 bar-H2. The impact of the Re promoter in the RuRe/C catalyst on the LA hydrogenation mechanism was also investigated for the first time using in situ FT-IR spectroscopy.

Hydrodeoxygenation of levulinic acid over Ru-based catalyst: Importance of acidic promoter

Biorefineries are fundamental for sustainable energy. This research explored the conversion of biomass-derived Levulinic acid (LA) into essential compounds γ-valerolactone (GVL) and 1,4-pentanediol (1,4-PDO) using the Ru2.5Mn15Al catalyst. The study underscores the role of Ru incorporation and specific promoters in enhancing catalyst efficiency. The crucial challenge is to destroy the particularly stable ring structure of GVL. The crucial roles of acidity and specific metal species in directing catalytic pathways were revealed by the detailed characterization of the catalyst's textural, acidic, reduction, and electronic properties. They provided valuable insights for sustainable chemical synthesis.

Catalytic Conversion of Levulinic Acid to Pyrrolidone under Mild Conditions with Disordered Mesoporous Silica-Supported Pt Catalyst.

Catalytic conversion of biomass-derived levulinic acid (LA) into high-valued 5-methylpyrrolidones has become an attractive case in studies of biomass utilization. Herein, we developed a disordered mesoporous Pt/MNS catalyst for this reductive amination process under room temperature and atmospheric pressure of hydrogen. The disordered mesoporous structures in support of Pt/MNS catalyst led the formation of highly dispersed Pt species via confinement effect, providing high specific area for enhancing the catalytic sites. With the synergistic effect between highly dispersed Pt species and mesoporous structures, 5-methylpyrrolidones were successfully synthesized from biomass-derived LA and primary amines with high selectivity. Mechanism studies indicated that introducing protonic acid would promote the reductive-amination process, and enamine intermediates could be detected during the in-situ DRIFT tests. Density functional theory (DFT) calculation confirmed that the hydrogenation of enamine intermediate was more accessible than that of imide intermediates, leading the excellent performance of the Pt/MNS catalyst. This work provided a green method to produce 5-methylpyrrolidone and revealed the impact of catalyst structural characteristics on the reaction process.

Catalytic Conversion of Biomass-Derived Levulinic Acid to γ-Valerolactone over Amphoteric Zirconium Hydroxide

Catalytic Conversion of Biomass-Derived Levulinic Acid to γ-Valerolactone over Amphoteric Zirconium Hydroxide

Catalytic Valorisation of Biomass-Derived Levulinic Acid to Biofuel Additive γ-Valerolactone: Influence of Copper Loading on Silica Support

γ-valerolactone (GVL) is a crucial chemical feedstock used in the production of fuel additives, renewable fuels, and fine chemicals alternative to petroleum-based solvents and chemicals, supporting the transition to sustainable energy solutions. It is promptly acquired by hydrogenating levulinic acid (LA) in a gaseous or liquid phase with a homogeneous or heterogeneous catalyst using a variety of recognized catalytic processes. Herein, this work focuses on the use of silica-supported copper (Cu/SiO2) catalysts for the gas-phase hydrogenation of LA to GVL under mild reaction conditions. The study analyzes how copper loading can affect the catalytic activity of the Cu/SiO2, while the flow rate of LA, time-on-stream, reaction temperature, and LA concentration affect the catalytic efficiency. The SiO2 support’s various Cu loadings are crucial for adjusting the catalytic hydrogenation activity. One of the studied catalysts, a 5 wt% Cu/SiO2 catalyst, demonstrated ~81% GVL selectivity with ~78% LA conversion and demonstrated stability for ~8 h while operating at atmospheric pressure and temperature (265 °C) and 0.5 mL/h of LA flow rate. The ability to activate hydrogen, high amount of acidic sites, and surface area were all discovered to be advantageous for increased GVL selectivity.

Conversion of levulinic acid and its esters to 1,5-dimethyl-2-pyrrolidone over a nonnoble metallic Ni@CeOx catalyst.

1,5-dimethyl-2-pyrrolidone (MNMP), as a highly efficient green solvent, can be obtained from biomass-derived levulinic acid and its esters with 100% conversion and 96.8% yield over a 10% Ni@CeOx catalyst at 140 °C, 2 MPa H2, 8 h, and with water as the solvent. Structure-property correlation investigations were performed with diverse characterization methods, including BET, XRD, XPS, TEM, HAADF-STEM, H2-TPR, NH3-TPD, CO2-TPD and FT-IR, and the results revealed that the excellent catalytic performance of the 10% Ni@CeOx catalyst was mainly resulted from the strong interaction between Ni and CeOx, which formed more catalytic active sites and contributed to higher reductive amination efficiency. Besides, the 10% Ni@CeOx catalyst had a chemisorption effect on LA. This was also the key to the excellent catalytic activity of the 10% Ni@CeOx catalyst. The 10% Ni@CeOx catalyst exhibited great stability throughout 6 reaction runs and excellent catalytic efficiency in the kilogram scale preparation of MNMP. This work provides a low-cost, efficient, and environmentally friendly heterogeneous catalytic system for the production of MNMP.

Ultrafine copper clusters confined in amino-functionalized mesoporous silica nanospheres for renewable biomass upgrading

The development of noble-metal-free catalysts for upgrading biomass feedstocks to chemicals and fuels remains a crucial and challenging target. Catalytic hydrogenation of biomass-derived levulinic acid (LA) to γ-valerolactone (GVL) is one of the essential reactions for biomass valorization. Herein, we report a confined Cu cluster catalyst, Cu/NMSSs-NH2, in which ultrafine Cu nanoclusters are uniformly encapsulated in the channels of amino-functionalized nanosized mesoporous silica spheres (NMSSs-NH2). The surface amino functionalization of NMSSs plays a critical role in dispersing and stabilizing Cu species. The obtained Cu/NMSSs-NH2 affords an excellent LA hydrogenation performance, with a GVL yield as high as 98% achieved, much higher than that of unconfined Cu particles in pristine NMSSs (Cu/NMSSs, 42%). Comprehensive characterization studies including X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy reveal that the modified microenvironment of NMSSs could not only offer a confined space but also induce an electronic interaction between metal species and the support, which effectively restrains the Cu nanoclusters from aggregation. This study unlocks the potential of inexpensive Cu cluster-based catalysts for the hydrogenation of renewable biomass to high-value chemicals.

Innovative Bioplasticizers from Residual Cynara cardunculus L. Biomass-Derived Levulinic Acid and Their Environmental Impact Assessment by LCA Methodology.

This work is focused on the application of Life Cycle Assessment (LCA) methodology for the quantification of the potential environmental impacts associated with the obtainment of levulinic acid from residual Cynara cardunculus L. biomass and its subsequent valorization in innovative bioplasticizers for tuning the properties as well as the processability of biopolymers. This potentially allows the production of fully biobased and biodegradable bioplastic formulations, thus addressing the issues related to the fossil origin and nonbiodegradability of conventional additives, such as phthalates. Steam explosion pretreatment was applied to the epigean residue of C. cardunculus L. followed by a microwave-assisted acid-catalyzed hydrolysis. After purification, the as-obtained levulinic acid was used to synthesize different ketal-diester derivatives through a three-step selective synthesis. The levulinic acid-base additives demonstrated remarkable plasticizing efficiency when added to biobased plastics. The LCA results were used in conjunction with those from the experimental activities to find the optimal compromise between environmental impacts and mechanical and thermal properties, induced by the bioadditives in poly(3-hydroxybutyrate), PHB biopolymer.

Highly Efficient Catalytic Hydrogenation of Biomass-Derived Levulinic Acid to Valeric Acid Over Ru/W/Al-SBA-15 Catalysts

Highly Efficient Catalytic Hydrogenation of Biomass-Derived Levulinic Acid to Valeric Acid Over Ru/W/Al-SBA-15 Catalysts

Hydrogen production from steam reforming of biomass-derived levulinic acid over highly stable spinel-supported Ni catalysts

Hydrogen production from steam reforming of biomass-derived levulinic acid over highly stable spinel-supported Ni catalysts

Selective Valorization of Bio-derived Levulinic Acid and Its Derivatives into Hydrocarbons and Biochemicals by Using Hydrosilylation.

Herein we report an efficient hydrosilylation strategy to selectively defunctionalize biomass-derived levulinic acid into value-added chemicals such as pentane-1,4-diol, pentan-2-ol, 2-MTHF and C5 hydrocarbons by using cost-effective silanes and the commercially available catalyst B(C6 F5 )3 at room temperature. All reactions work well in chlorinated solvents but, as a greener alternative, most reactions can be run in toluene or solvent-less.

Insights into structure–activity relationships in efficient silica-supported Ni catalysts for selective hydrogenation of levulinic acid

Upgrading biomass-derived levulinic acid (LA) with greater carbonyl (CO) group activation is crucial in converting biomass and its derivatives into valuable biochemicals and biofuels.

Highly efficient Ni–Mn/SiO2 catalyst for the selective hydrogenation of biomass-derived levulinic acid to γ-valerolactone under mild conditions

Herein, we report a highly efficient non-noble bimetallic Ni–Mn/SiO2 catalyst for the selective hydrogenation of biomass-derived levulinic acid to γ-valerolactone under mild reaction conditions.