MPa H2 Research Articles

Highly efficient hydrogenation of phenol and lignin-derived compounds over Ru-Rh bimetallic nanoparticles supported on α-Al2O3 at room temperature

Catalytic hydrogenation of phenol and lignin-derived compounds is an important strategy to produce chemical and pharmaceutical intermediates, but it is still a challenge to achieve this process under mild conditions. Herein, the bimetallic Ru-Rh/α-Al2O3 catalyst was successfully prepared and used for the direct hydrogenation of phenol and lignin-derived compounds. The results of this study illustrate that Ru-Rh/α-Al2O3 exhibits the highest activity for the hydrogenation of phenol and diphenyl ether among these catalysts. Phenol can be completely converted to the target product of cyclohexanol over Ru-Rh/α-Al2O3 under extremely mild conditions (30 °C, 1 MPa H2, 90 min). With Ru-Rh/α-Al2O3 as the catalyst, a variety of other unsaturated substrates are also efficiently hydrogenated to the corresponding ring-saturated products with a high yield. The characterizations reveal that the strong interaction formed between Ru and Rh is mainly responsible for the enhancement of the hydrogenation activity. The construction of the bimetallic Ru-Rh/α-Al2O3 catalyst can accelerate the high value-added utilization of phenol and lignin-derived compounds.

Hyper-crosslinked polymer derived porous Co@CN catalyst for selective hydrogenation of quinoline

A benzotrizole-based hyper-crosslinked polymer (HCP) was employed to load cobalt and prepare a novel metal-containing nitrogen-doped carbon catalyst for the selective hydrogenation of quinoline. The high porosity, large surface area and nitrogen-containing monomer of HCP made a positive contribution to metal loading. Owing to the excellent thermostability of HCP, the original porous texture of HCP was partially reserved during pyrolysis, which resulted in highly dispersive Co species in the N-doped carbon material. The remaining mesopores in Co@CN catalyst during thermal decomposition provided available diffusion channels for substrates, which facilitated their full contact with catalytic active sites and their effective conversion. The prepared Co@CN catalyst achieved a conversion rate of 100% and a selectivity of 100% in the hydrogenation of quinoline into 1, 2, 3, 4-tetra-hydroquinoline in water at 100 °C under 3 MPa H2. The as-synthesized catalyst had good reuse performance, exhibiting >95% conversion rate and >99% selectivity even after 12 cycles. Moreover, the catalyst could also be applied to the selective hydrogenation of a serial of quinoline derivatives. The study provided a useful strategy for constructing metal-doped carbon materials which might be applicable for other metals and other reactions.

Synergistic effect of surface Cu0 and Cu+ species on improved selective hydrogenation of furfural to furfuryl alcohol over hydrotalcite-derived CuxMg3Al oxides

In the selective hydrogenation of furfural (FAL) to furfuryl alcohol (FOL), it is important to develop a simple and cheap non-precious metal catalyst to replace the precious metal catalyst. Therefore, CuxMg3AlOy (x = 0.3, 0.5, 0.7, 0.9, 1.1) composite metal oxide catalysts were prepared by CuMgAl-LDHs as precursor for the selective hydrogenation of FAL to FOL. In this series of catalysts, Cu0.9Mg3AlOy has the best catalytic activity, with 99% FAL conversion and 98.4% selectivity under the mild reaction conditions of 1.6 MPa H2 pressure, 1.5 h and 120 ℃, and good reusability. XRD, TEM, H2-TPR, CO2-TPD, XPS and in-situ DRIFTS characterization were used to investigate the activate species for hydrogenation reaction. It can be proved that Cu2+ and Cu+ on the surface of CuxMg3AlOy can be partially reduced to the Cu0 species in-situ during the reaction, promoting the hydrogenation of FAL. Various studies confirm that Cu0 is mainly responsible for the activation and dissociation of H2, and both Cu0 and Cu+ are used to adsorb the carbonyl group in FAL to improve the selectivity of FOL. Moreover, the appropriate amount of the Cu0 and Cu+ species plays an important role in selective hydrogenation of FAL to FOL through their synergy.

Atomic-Dispersed Rh Enables Efficient Catalytic Nitrile Hydrogenation: Size Effect and Metal-Dependent Effect

The hydrogenation of nitriles to amines, as an atom-economical synthetic route, has attracted wide attention in industrial production. Despite that some catalysts for nitrile hydrogenation have been investigated in recent years, achieving high activity and selectivity in this process remains a major challenge. Here, we fabricated an atomically dispersed Rh catalyst anchored on defect-rich nanodiamond-graphene (ND@G) via a deposition–precipitation strategy (Rh1/ND@G), which showed the highest activity (TOF = 2592 h–1) in the hydrogenation of benzonitrile reaction among all the known catalysts under mild reaction conditions (333 K, 0.6 MPa H2), and delivered high selectivity (>99%) toward secondary amines. Significantly, we prepared the Rh-cluster catalyst (Rhn/ND@G) and a series of atomically dispersed M1 catalysts (M = Rh, Ru, Pd, Ir, and Pt) to understand the size effect and metal-dependent effect in the hydrogenation of benzonitrile. Experimental and theoretical investigations revealed that the Rh1/ND@G catalyst has higher selectivity toward dibenzylamine than Rhn/ND@G, as it is less likely to form benzylamine on the Rh1 active sites. Meanwhile, the difference of adsorption energies (as a catalyst descriptor) between benzylideneimine and benzonitrile was used to understand the activity of benzonitrile hydrogenation influenced by the metal-dependent effect of M1 catalysts. Modulating the size and metal-dependent effects could lead to high catalytic performance, paving the way to design efficient nitrile hydrogenation catalysts.

Metal-organic framework-derived Co-C catalyst for the selective hydrogenation of cinnamaldehyde to cinnamic alcohol

The liquid phase selective hydrogenation of cinnamaldehyde has been investigated over the catalysts Co-C-T (T = 400–700 °C), which were derived from the carbonization of the MOF precursor Co-BTC at different temperatures in inert atmosphere. Co-C-500 exhibited a higher conversion (85.3%) than those carbonized at other temperatures, with 51.5% selectivity to cinnamyl alcohol, under a mild condition (90 °C, 4 h, 2 MPa H2, solvent: 9 ml ethanol and 1 ml water). The high catalytic activity of Co-C-500 can be ascribed to the large specific surface area of the catalyst, the uniformly dispersed metallic cobalt nanoparticles, and the more defect sites on the carbon support. Moreover, Co-C-500 showed excellent reusability in 5 successive cycles, mainly related to the uniformly dispersed cobalt nanoparticles embedded in carbon support.

Synthesis of Co―N―C catalysts from a glucose hydrochar and their efficient hydrogenation of nitrobenzene

A low-cost, green catalyst for nitrobenzene (NB) hydrogenation is needed for aniline production. We report the preparation of highly-dispersed Co particles supported on N-doped carbons by the hydrothermal treatment of glucose, followed by the pyrolysis of a mixture of urea, glucose hydrochar and cobalt nitrate in one-pot. The effect of the pyrolysis temperature on the microstructure of the catalysts was studied. Results indicated that the activity for NB hydrogenation was highly affected by the surface area, Co-loading level and Co-Nx coordination in the catalysts. Co@NCG-800 pyrolyzed at 800 °C with 10% Co in the precursor had extraordinary activity for NB hydrogenation, achieving full conversion and 99% aniline selectivity in isopropanol at 100 °C and 1 MPa H2 pressure for 2.5 h. NB conversion and aniline selectivity over the catalysts remained almost unchanged after six recycles, due to the strong coordination between the N- and Co-species. The reaction system showed not only a high NB activity but also a green and durable catalytic process, with easy operation, easy separation and catalyst reusability.

Effect of solvent systems on the synergistic catalytic hydrogenolysis of alkaline lignin over Pd/C-NaOH

Solvents and catalysts are two of the most critical factors for the depolymerization of lignin. This paper investigated the effect of different pure solvents on the hydrogenolysis of the β-O-4 MC and one of the mixed solvents on the hydrogenolysis of alkaline lignin. It was found that MC had higher conversion (96.5% and 94.3%) and monophenol yield (83.4 wt% and 77.9 wt%) in ethanol and 1,4-dioxane. The effects of different ratios of mixed solvents (ethanol-H2O and 1,4-dioxane-H2O), reaction conditions (temperature, time, pressure), and the synergistic effect of alkali and Pd/C catalysts on the hydrogenolysis of alkaline lignin were investigated in this paper. The composition, structure, and distribution of the lignin degradation products were also analyzed by GC, GC–MS, GPC, FT-IR, and 2D-HSQC. The results showed that the optimum monomer yields were 37.5 wt% and 24.7 wt% for ethanol-H2O and 1,4-dioxane-H2O at 3:2 (v:v) and 2:3 (v:v), respectively. The optimum yields were obtained at 260 °C, 2 MPa H2, and 4 h. The properties of solvent (protic polar solvent, nonpolar aprotic solvent) could influence the hydrogenolysis greatly and selectively break bonds. The different ratios of solvents in the mixed solvent systems influenced the solubility of alkaline lignin and its hydrogenolysis results. In addition, the synergistic effect of Pd/C and NaOH could improve the monomer yield and inhibit the polymerization of intermediates in hydrogenolysis.

Catalytic valorisation of the effluents generated during the defibrillation process of cellulose from almond hulls: A holistic zero-waste biorefinery approach

The acid-free hydrothermal microwave–assisted selective scissoring (Hymass concept) of cellulosic substrates is gaining keen interest in the field of materials science. Besides, implementing catalytic methodologies to upgrade side streams produced during this process could contribute to better, holistic utilisation of the starting feedstock. This work depicts a zero-waste biorefinery concept based on cellulose defibrillation from almond hulls using various hydrotreatment technologies (hydrogenation and hydrodeoxygenation) for downstream processing on a ruthenium catalyst. Therein, the hemicellulose separated from the biomass preconditioning step was converted into sugar alcohols and/or marketable polyols with a relatively high yield (47.4%) by hydrolytic hydrogenation (437 K, 3h, 5.0 MPa H2). Meanwhile, a family of bioactive compounds (3-hydroxypyridines) could be directly extracted from the hydrolysate stream derived from microwave digestion, along with an energy carrier that was chemically stabilised (503 K, 60 min, 4.0 MPa H2) to obtain fuel additives (diethyl succinic acid, DES) and/or fuel intermediates.

Regulating the Cu0-Cu+ ratio to enhance metal-support interaction for selective hydrogenation of furfural under mild conditions

Controllable carbonyl group (CO) hydrogenation is the key to the transformation of furfural molecules into high-value furfuryl alcohol chemicals. Herein, a non-noble copper metal catalyst (Cu/MgO) was prepared for the efficient hydrogenation of furfural to furfuryl alcohol under mild conditions. At 383 K and 2 MPa H2, 99.9% conversion of furfural with 99.9% selectivity to furfuryl alcohol was achieved within 80 min while the turnover frequency (TOF) was 56.87 h−1. The temperature of a reductive pretreatment can be used to tune the nature of the interfaces between reduced copper and the metal oxides present in copper-magnesium oxide catalysts. The valence copper species exhibited unique catalytic properties in the hydrogenation of furfural to furfuryl alcohol. Besides, the Cu/MgO-350 exhibited excellent stability and reusability without significant activity loss. These results were accounted for by the MgO alkaline interface contributing to the effective formation and high dispersion of different valence Cu species. The active site had strong adaptability to the adsorption of reactants and desorption of products, thus avoiding excessive hydrogenation of furfural. According to the analysis of the characterization data, furfural adsorption mainly existed in η1(O)-aldehyde binding mode which was consistent with the density functional theory (DFT) calculation. DFT calculations of the reaction process showed that the theoretical results favored the hydrogenation of furfural through a hydroxyalkyl intermediate rather than of an alkoxide intermediate.

Cinchona-Alkaloid-Derived NN Ligands and Achiral Phosphines for Iridium-Catalyzed Asymmetric Hydrogenation of Heteroaromatic and α-Chloroheteroaryl Ketones.

A concise synthesis of cinchona-alkaloid-derived NN ligands bearing alkyl substituents on chiral nitrogen atoms was described. Iridium catalysts containing new chiral NN ligands and achiral phosphines were effective for the asymmetric hydrogenation of heteroaromatic ketones, which afforded corresponding alcohols in up to 99.9% ee. The same protocol was applicable to the asymmetric hydrogenation of α-chloroheteroaryl ketones. Most importantly, the gram-scale asymmetric hydrogenation of 2-acetylthiophene and 2-acetylfuran proceeded smoothly even under 1 MPa of H2.

In situ construction of 3D NiMo bimetallic catalysts anchored on dendritic mesoporous silica for the upgrading of biomass derivatives

Reasonable construction of bi-function catalysts with well dispersed hydrogenation active sites and acidic sites are crucial for the hydrodeoxygenation (HDO) of biomass-derived compounds but still a huge challenge. Herein, a 3D Mo functionalized Ni-based bimetallic embedded catalyst with fine metal nanoparticles size (<6 nm) was prepared for the first time using dendritic mesoporous silica as a sacrificial template by one-pot hydrothermal synthesis and adopted in the HDO process of vanillin (VAN) upgrade to 2-methoxy-4-methylphenol (MMP). The characterization results illustrated that Mo species regulated the acidity of the catalyst and promoted the formation of Ni-Mo alloy sites. Density functional theory (DFT) calculations further unveiled that Ni-Mo alloy sites promoted the activation and dissociation of CO bond in VAN, enhanced the ability of protonation hydrogenolysis. Benefitting from the synergistic effect of the highly uniformly dispersed hydrogenation metal sites and acidic sites, nearly 100% yield of MMP could obtained over the designed catalyst under mild conditions (130 °C, 1.5 MPa H2, 3 h, 10 wt% catalyst dosage). Additionally, the NiMo0.1@MSN catalyst displayed robust activity for no less than 8 recycles and excellent universality for the HDO of a variety of lignin derivatives and biomass platform molecules, which provide a feasible strategy for the construction of 3D confined catalysts for the high-efficiency HDO of biomass derivatives.

Effect of Lewis and Brønsted acidity in Ni/ZSM-5 on catalytic reductive etherification of furfural and alcohols

Reductive etherification is an attractive and practical strategy to convert bio-platform compounds into valuable chemicals. In directed synthesis of furfuryl ethers, reductive etherification of bioderived furfurals is still challenging due to the complexity of catalytic reaction. Herein, reductive etherification of furfural with alcohol was investigated over Ni/ZSM-5 catalyst, which found that Si/Al ratios in ZSM-5 played an important role on the catalytic performance. For Ni/ZSM-5 with Si/Al ratio of 50, 80.9% yield of furfuryl ether at 90.8% conversion of furfural was achieved under the condition of 2 MPa H2 and 180 °C for 3 h in isopropanol. The catalyst exhibited superior stability and recyclability during the consecutive cycle run. Catalysts characterization demonstrated that both acidic properties and furfural adsorption were influenced by the Si/Al ratios in Ni/ZSM-5, which correlated to the reaction route and catalytic performance. Lewis acid sites enhanced furfural hydrogenation into furfuryl alcohol, while Brønsted acid sites on ZSM-5 effectively catalyzed sequential etherification of furfuryl alcohol to furfuryl ether. Under optimization conditions, various furfuryl ethers could be obtained with yields above 80% over Ni/ZSM-5 catalyst in different primary alcohols, demonstrating the general versatility of the approach. Our findings offered opportunities to develop an efficient furfuryl ethers synthesis method.

Selective hydrogenation of diphenyl ethers over NiCo bimetallic catalyst

The selective cleavage of ether bonds by non-noble metal catalysts is crucial for the valorization of lignin. Bimetallic catalysts were prepared by wet impregnation using SiO2-Al2O3 as the supports and Ni and Co as the active metal sites. The prepared bimetal catalysts possess higher catalytic activity than single Ni or Co catalysts and could efficiently cleave the CO bonds of diphenyl ether (DPE), under relatively mild conditions (160 °C, 1 MPa H2, 2 h). The XPS characterization suggested the interactions between Ni and Co in the bimetal catalysts, which could bring synergy effects between metals and increase the catalytic activity. The H2-TPR analysis confirmed that the presence of Ni lowered the reduction temperature of Co oxides in the bimetallic xNiyCo/SA catalyst compared to the monometallic Co/SA catalyst, which would increase the amount of metallic Co. Based on the product distribution, it could be proposed that the hydrogenation of DPE over catalyst 15Ni15Co/SA was mainly via the reaction path of “partial hydrogenation-hydrogenolysis-hydrogenation" process. The catalytic activity of catalyst15Ni15Co/SA could be recovered after regeneration. It also exhibited versatility for the cleavage of other CO bonds.

Efficient synthesis of sugar alcohols using a composite trimetallic Pt–Ni–Sn/MWCNTs catalyst based on metal element coordination and valence regulation

Functional sugar alcohols are a kind of burgeoning food additives to substitute saccharose due to the prominent biofunctions including moderate sweetness, low calorific values and no influence on blood sugar fluctuation, thus applied widely in food, medical, health protection as well as chemical production. Traditional synthesis of functional sugar alcohols required high temperature and H2 pressure, as well as leading to low reaction efficiency, side reactions and leaching of toxic metal ions. In the present work, Pt–Ni–Sn/MWCNTs catalyst was obtained using a liquid phase reduction method with the transition metals loading of Pt 3.4%, Ni 0.7%, Sn 0.4%, respectively. The catalyst catalyzed the preparation of xylitol, sorbitol, mannitol and galactitol with the high monosaccharide conversion (>99.5%) and yield (>99.1%) under relatively mild conditions (100 °C, 3.0 MPa H2), which were lower than ever reported. For the 13-batch reuse of Pt–Ni–Sn/MWCNTs, the total conversion of xylose was 99.4% and the total yield of xylitol was 99.2%, the productivity of 103.2 g xylitol per gram of catalyst was also obtained. Besides, no side reactions, no metal ions as well as no changes of pH were observed in the reaction process. Our trimetallic catalyst exhibited valuable potential in functional sugar alcohols production.

Copper nanoparticles encapsulated in a nanoporous carbon-based catalyst in the upgradation of γ-valerolactone to 1,4-pentanediol by selective hydrogenation

This research work introduces highly dispersed Cu nanoparticles encapsulated into a nanoporous carbon (Cu@C) structure as an efficient catalytic system in selective hydrogenation of γ-valerolactone (GVL) to 1,4-pentanediol. The nanoporous carbon support and the catalysts were synthesized by sequential novel methods and characterized extensively by using a combination of different analytical techniques to determine the phase, textural, morphology, nanoparticles size, and distribution analysis, and redox behavior. The designed Cu@C embedded catalysts show moderately high activity in GVL hydrogenation with different Cu loadings. The effect of copper loadings was found to be a significant parameter in gaining the best performance in GVL conversion. The copper nanoparticles were uniformly distributed over the nano-scaled carbon structure with active metallic Cu(111) sites with high dispersion and promote GVL hydrogenation, efficiently. Over a 5Cu@C catalyst exhibited the highest GVL conversion (∼91%) and 1,4-pentanediol selectivity (∼97%) at 200 °C for a 5 h reaction time under a 5 MPa H2 pressure. The dispersion of the active copper phase in combination with a smaller particle size and surface acidity is directly correlated with the catalytic performance activity. The effects of reaction parameters such as the reaction time, temperature, and H2 pressure were systematically investigated. Overall, Cu@C is a promising non-noble metal-based catalytic system for the upgradation of biomass-based platform molecules via selective hydrogenation.

Changes in structural parameters of SARA fractions during heavy oil hydrocracking using dispersed catalysts

Most of the characterization of SARA fractions of heavy crude oils during hydrocracking reactions is focused only on asphaltenes, and scarce works are devoted to analyze the differences in the structural parameters of all SARA fractions. In this work, a heavy crude oil is upgraded by non-catalytic and catalytic hydrocracking in a batch reactor at low severity conditions (3.9 MPa H2 pressure, 380 °C temperature, 800 rpm stirring rate, and 4 h reaction time). Three ore catalysts (hematite, magnetite and molybdenite) and one analytical grade catalyst (iron oxide) are employed. After reaction, the upgraded oils are first distilled and then separated into SARA fractions by the ASTM D86-16a and ASTM D2007-11 methods, respectively. NMR (1H and 13C), FTIR and GPC analyses are used to characterize SARA fractions before and after hydrocracking. The hydrocracking products exhibited a reduction in the average molecular weight of all SARA fractions as function of the hydrogenation capacity of each catalyst in the following order: Fe2O3 (analytical grade) > Molybdenite > Hematite > Magnetite. The structural parameters of saturates fraction remains unchanged except for the production of small length aliphatic chains from heavier fractions. For aromatics, resins and asphaltenes fractions, the number of aliphatic carbons is reduced due to dealkylation reactions increasing their aromaticity. For resins and asphaltenes fractions, hydrogenation and ring opening reactions are also carried out. Mo-based catalyst is mainly aimed at the conversion of asphaltenes, while the Fe-based catalysts focused on the conversion of resins.

Ultrauniform Ru Nanoclusters as Efficient Hydrogenation Catalysts for Phthalates

Cyclohexane dicarboxylic acid (CHDA) ester, a kind of environmental-friendly plasticizer, can be produced by phthalates hydrogenation. However, the synthesis of catalysts with high activity and selectivity is a challenge due to the stability of aromatic rings. In this work, a series of ultrauniform Ru nanoclusters supported by γ-Al2O3 are synthesized for the hydrogenation of diisononyl phthalate (DINP). Results show that the conversion of DINP and the selectivity of diisononyl-cyclohexane-1,2-dicarboxylate (DINCH) both reach 100% at 140 °C and 3 MPa H2 pressure. Diisononyl-cyclohexene-1,2-dicarboxylate (4H-DINP) and 1,2-cyclohexanedicarboxylate-7-methyloctyl ester are found; the hydrogenation reaction network of DINP is constructed. Alkali metal ions adsorbed on the surface of Ru nanoclusters prepared by the polyol method can stabilize Ru3+-Hδ− species by electrostatic interaction, thus affecting the hydrogenation activity of the catalyst, following the order of Li+ > Na+ > K+ > Cs+. Ru-based catalysts prepared by the polyol method have good prospects for application in phthalates hydrogenation.

Selective Hydrogenation of Naphthalene to Produce Tetralin over a Ni/S950 Catalyst under Mild Conditions

Tetralin is an essential chemical that can be generated by the partial hydrogenation of naphthalene. However, it is a challenge to design a catalyst with high efficiency, low-temperature activity, high tetralin selectivity, and a low cost to produce tetralin. A Ni/S950 catalyst with well-dispersed metal particles and high catalytic activity was prepared with an ion-exchange method. A complete conversion of naphthalene and a high tetralin yield of 95.6% were achieved over the Ni/S950 catalyst under 200 °C, 2 h, and 2 MPa H2. Compared with Co/S950 and Cu/S950, both the hydrogenation activity and the selectivity of tetralin over Ni/S950 are much higher due to its well-dispersed Ni particles with a smaller particle size of 6.8 nm and numerous active Ni0 sites.

Green and highly selective hydrogenation of lignin-derived aromatics at low temperature over Ru-Fe bimetallic nanoparticles supported on porous nitrogen-doped carbon

Low temperature and highly selective hydrogenation of the lignin-derived aromatics to obtain high-value chemicals and clean liquid fuels is a significant step for lignin valorization in the chemical industry. Developing efficient catalysts with high activity and selectivity for hydrogenation of lignin-derived aromatic rings at low temperature remains a big challenge. Herein, a well-dispersed Ru-Fe bimetallic nanoparticle catalyst supported on porous nitrogen-doped carbon was developed through a facile impregnation method. It showed excellent catalytic activity for hydrogenation of lignin-derived aromatics, such as diaryl ethers, phenolic monomers and arenes to corresponding alicyclic compounds with high selectivity, under surprisingly mild conditions (≤50 °C, ≤2 h and 1 MPa H2). Hydrogenation of aromatic rings took precedence over the cleavage of C-O bond for the lignin-derived aromatics. The resulting alicyclic compounds are key raw materials for synthesizing polymer, pharmaceutical intermediates and resins, and clean liquid fuels. The strong interactions between metal and support improved the anti-oxidation and anti-sintering ability of the catalyst, and significantly improve the hydrogenation performance. Additionally, the phenols in the lignin oil were effectively converted into cyclohexanol and its derivatives at 90 °C over the Ru-Fe bimetallic catalyst, with selectivity up to 53.3% in the hydrogenated lignin oil. The development of this catalyst for selective hydrogenation of lignin-derived aromatics at low temperature provides a green, low carbon footprint and sustainable approach for the value-added utilization of lignin and its derivatives.

Catalytic hydrogenation of levulinic acid to γ-valerolactone over lignin-metal coordinated carbon nanospheres in water

The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) has attracted much attention, as GVL can be used as biofuel, green solvent, and platform chemical. Inspired by Stöber method, various lignin-metal coordinated colloidal nanospheres (LCS) from lignin and cetyltrimethylammonium bromide (CTAB) were synthesized in which the metal ions (Co2+) replace formaldehyde as the crosslinker. The characterization of the catalyst revealed that alkali lignin was first self-assembled with CTAB through electrostatic attraction to form a lignin polymer, the subsequent addition of metal ions (Co2+) promoted the aggregation of lignin polymers and generated the LCS. Increasing calcination temperature for LCS resulted in the Co2+ being reduced to metallic Co. The lignin-metal coordinated colloidal nanospheres calcined at 500 °C possess both CoO and metallic Co active sites, which effectively accelerated the hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) than simplex metallic Co active sites. A 99.8 % yield of GVL with 100 % LA conversion was obtained after 60 min reaction time at 200 °C and 2 MPa H2.