MPa H2 Research Articles

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.

Highly efficient, amorphous bimetal Ni-Fe borides-catalyzed hydrogenolysis of 5-hydroxymethylfurfural into 2,5-dimethylfuran

Designing highly efficient non-noble metal catalyst for the selective hydrogenolysis of biomass derivatives to fuels and fine chemicals is a key pursuit for sustainable chemical industry but substantially challenging. In this contribution, we report, for the first time, the construction of amorphous bimetal Ni–Fe borides for efficient catalytic hydrogenolysis of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dimethylfuran (DMF) as a promising biofuel candidate. The as-prepared Ni1.52Fe0.36BOx catalyst afforded a near-quantitative DMF yield using ethanol as a green solvent under relatively mild operating conditions (1 MPa H2, 160 °C and 1 h), leading to an excellent DMF formation rate of 16.5 mmolDMF·gcat−1·h−1, which is 1.7–16.5 folds higher than the state-of-art nickel-based catalysts. Mechanistic investigations demonstrated that the Fe intervention is conductive to the generation of electron-enriched metal sites and powerful acidic sites in Ni1.52Fe0.36BOx catalyst, which favored the activation of hydrogen and the cleavage of C–O bond to accelerate the hydrogenolysis process. Moreover, Ni1.52Fe0.36BOx catalyst exhibited good recyclability as well as universality in the hydrogenolysis of various biomass-derived unsaturated aldehydes. This finding opens a new avenue for highly selective hydrodeoxygenation of renewable biomass feedstock to value-added chemicals with non-noble bimetal hybrids in a green and straightforward manner.

Selective Hydrogenation of Nitrobenzene to para-Aminophenol on a Zirconium-Phosphate-Supported Platinum Catalyst

In this work, zirconium-phosphate-supported platinum catalysts have been prepared by a wetness impregnation method and characterized thoroughly by various methods. The 1%Pt/ZrP catalyst displayed superior catalytic performance for the selective hydrogenation of nitrobenzene. It was found that the formation rate of para-aminophenol was much higher than that of aniline over the catalyst in the presence of inorganic acid and DMSO. A full conversion of nitrobenzene and high selectivity to para-aminophenol (89%) were achieved under mild reaction conditions (80 °C, 0.6 MPa H2). Also, the catalyst can be recycled in 14 consecutive catalytic runs without any obvious decrease in activity and selectivity for the hydrogenation of nitrobenzene. The electron transfer interaction of Pt(0) species with zirconium phosphate accounted for the high dispersion and leaching resistance of the Pt sites, leading to excellent recyclability of the catalysts. The further characterization by in situ DRIFT demonstrated that the nitro functional group was dominantly adsorbed on acid sites of zirconium phosphate and reduced to N-phenylhydroxylamine by spillover hydrogen, followed by rearrangement to afford para-aminophenol.

Morphology evolution of bimetallic Ni/Zn-MOFs and derived Ni3ZnC0.7/Ni/ZnO used to destabilize MgH2

Herein, 3D porous flower-like Ni/Zn-MOFs are synthesized via a simple solvothermal method. The reaction time shows obvious effects on the morphology evolution of Ni/Zn-MOFs, and the morphology evolution from plate to 3D flower is governed by a “nucleation–dissolution–renucleation” mechanism. Nonstoichiometric bimetallic carbide-containing composites (Ni3ZnC0.7/Ni/ZnO composites) are obtained through the simple calcination of Ni/Zn-MOFs under 4 MPa H2, suggesting that ZnO cannot be reduced and Ni3ZnC0.7 is stable even under 24 h of hydrogen treatment. The MgH2-5 wt% Ni3ZnC0.7/Ni/ZnO-3 composite began to dehydrogenate at 230 °C and 5 wt% H2 can still be released within the initial 1 h at 573 K. The hydrogen absorption capacity of the composite reached 2.57 wt% H2 at 423 K within 600 s. Interestingly, the composite can still absorb 0.78 wt% H2 at 353 K within 60 min. Compared to pure MgH2, the activation energy (Ea) of hydrogen absorption and dehydrogenation of the composite decreased to 44.85 and 93.06 KJ/mol, respectively. Comparing the cases of Ni3ZnC0.7, Ni, and ZnO addition clearly reveals that Ni3ZnC0.7 and Ni are the primary catalysts in these improvements. The Ni3ZnC0.7/Ni/ZnO-3 composite will react with MgH2 during the absorption–desorption cycle, and the in situ generated Mg2Ni/Mg2NiH4 acts as a “hydrogen pump” to reduce the potential barrier for the dissociation and recombination of H2. Trace amounts of MgZn2 can promote the formation of Mg/MgH2 and the resulting minor expansion and contraction during phase changes provides more paths for hydrogen diffusion. This study clearly demonstrates the efficient catalytic activity of nonstoichiometric bimetallic carbides and provides a promising catalyst design for Mg-based hydrogen storage materials.

Synthesis of Mesoporous Silica-Supported NiCo Bimetallic Nanocatalysts and Their Enhanced Catalytic Hydrogenation Performance.

In this work, mesoporous silica SBA-16-supported NiCo bimetallic nanocatalysts were synthesized by coimpregnation of Ni and Co precursors followed by calcination and reduction, and various characterization techniques confirm the formation of NiCo bimetallic nanostructures in the catalysts. The synthesized NiCo/SBA-16 shows enhanced catalytic performance for hydrogenation of a series of nitroaromatics. Under the reaction conditions of 80 °C and 1.0 MPa of H2, the yields of aniline for nitrobenzene hydrogenation over NiCo0.3/SBA-16 can reach more than 99% at 2.0 h. The enhanced catalytic performance can be ascribed to the formation of NiCo bimetallic nanostructures, where the synergistic effect between Ni and Co improves their catalytic activities for hydrogenation of nitroaromatics.

Sustainable production of dimethyl-protected cyclic lysine over Pd/m-Al2O3-Si catalysts and its application in synthesis of antibacterial nylon‑6 copolymers

Antibacterial monomers are prerequisites for synthesizing antibacterial polymers, especially during the current COVID-19 pandemic. Dimethyl-protected cyclic lysine (DMCL) is a promising functional monomer for nylon-6 based self-cleaning antibacterial polymers. However, the production of DMCL still faces formidable challenges, such as harsh reaction conditions and low catalyst activities. In this study, we developed a Pd/m-Al2O3-Si catalyst, which exhibited high efficiency in converting α-amino-ε-caprolactam (α-ACL) to DMCL, affording a yield of as high as 97.1% at 100 °C and 1 MPa H2. The lack of Brönsted acid sites on the catalyst surface facilitated the formation of DMCL and suppressed undesirable hydrolysis or cracking by-products from the lactam-based reactant. The recycled experiments showed that Pd/m-Al2O3-Si performed excellent stability and physical strength with essentially no damage to its microspheres after the reaction. The nylon‑6 copolymers produced from the as-synthesized DMCL exhibited similar structure and thermal stability with pure nylon-6, showing great potential in synthesizing the self-cleaning antibacterial polymers. This work provides a sustainable and efficient method for producing DMCL and other lysine-based antibacterial monomers, showing a great prospect for the utilization of bio-based chemicals in synthesizing functional polymers.

The solvent-free hydrogenation of butyl levulinate to γ-valerolactone and 1,4-pentanediol over skeletal Cu-Al-Zn catalyst

γ-valerolactone (GVL) is a sustainable chemical, which can be obtained by hydrogenation of levulinic acid (LA) and levulinate. Herein, we reported a solvent-free hydrogenation of butyl levulinate (BL) to GVL and 1,4-pentanediol (1,4-PDO) over a skeletal Cu-Al-Zn catalyst. The skeletal Cu-Al-Zn catalyst was prepared from Devarda's alloy by alkali leaching and the catalyst was characterized by different analysis methods. The aluminum in the Devarda's alloy was dissolved by sodium hydroxide in the leaching process and many active Cu atoms were generated on the catalyst surface and the skeletal Cu-Al-Zn exhibited many micrometer-scale irregular particles with rough surface. The skeletal Cu-Al-Zn catalyst showed the excellent performance in the solvent-free hydrogenation of BL to GVL under constant hydrogen pressure (5 wt% catalyst loading, 180°C, 6 MPa of H2, 6 h): the LA conversion was 100%, the GVL yield was 74.75% and the 1,4-PDO yield was 25.63%. Moreover, the catalyst showed stable performance and it was reusable up to 5 times without apparent loss of activity. A stable hydrogen pressure with Zn would suppressed the dehydration of 1,4-PDO.

Highly active and stable CoWS2 catalysts in slurry phase hydrocracking of vacuum residue: XAFS studies

The bimetallic CoWS2 catalysts were prepared in situ during the slurry phase hydrocracking (HCK) of vacuum residue (VR) using W(CO)6 and Co-octoate as oil soluble precursors to investigate the promotional effect of Co promoters on the dispersed WS2 catalyst for the VR HCK. The morphologies and structural properties of dispersed catalysts were characterized by transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS). The bimetallic CoWS2 catalyst was observed to form well-dispersed monolayers in the size range of 7–11 nm, which showed higher turn-over frequency values (TOF) and C7-asphaltene (C7-ASP) conversions than monometallic WS2 or Co9S8 catalysts in the VR HCK at 693 K and 10.0 MPa H2. Moreover, the extended X-ray fine absorption structure spectroscopy (EXAFS) coupled with the density functional theory (DFT) calculations successfully verified the formation of the Co-W-S phase.

Synthesis of etheric ester based biofuel additive over bifunctional metal/zeolite catalysts comprising NiRe nanoparticles and Beta zeolite

Biomass derived etheric ester compounds show promising applications as renewable fuel additives and solvents. In this study, we reported the preparation of bifunctional transition metal/zeolite catalysts comprising Ni-Re bimetal nanoparticles and Beta zeolites prepared via conventional wet-impregnation method. The bifunctional nature makes it possible for the synthesis of ethyl-4-ethoxy pentanoate (EEP) as etheric ester starting from ethyl levulinate (EL) in presence of H2 with good performance. The textural properties and acidity of the catalysts were characterized by several techniques: XRD, TEM, STEM-Mapping, H2-TPR and XPS. The addition of ReOx increased the dispersion and reducibility of NiO·NH3-TPD and in-situ FT-IR of pyridine adsorption confirmed that the NiReOx/Beta catalyst affords large amount of Lewis acid sites and certain amount of Bronsted acid sites. The attained Bronsted acid sites in BEA topology may be the key sites contributing to the etherification. Under optimized reaction conditions, namely 160 °C, 1 MPa H2 and reaction time of 2 h, almost full conversion of EL with 83% yield of EEP could be achieved in ethanol.

Ni-Mg/Al Mixed Oxides Prepared from Layered Double Hydroxides as Catalysts for the Conversion of Furfural to Tetrahydrofurfuryl Alcohol

Ni-Mg/Al mixed oxide catalysts (Ni2Al, Ni2Mg1Al, and Ni1Mg1Al) obtained from layered double hydroxides (LDHs) were tested on the one-pot production of tetrahydrofurfuryl alcohol (TFA) from furfural (FF). Upon calcination at 400 °C and reduction at 500 °C, the LDHs gave catalysts containing small nickel crystallites (<4 nm) dispersed on mixtures of metal oxides and spinel structures. Complete conversion of FF (>99.5%) was achieved on all the catalysts after 4 h at 190 °C and 5.0 MPa of H2 using 5 wt.% FF in ethanol and a furfural-to-catalyst mass ratio of 7.44 g/g. TFA evolved from the sequential hydrogenation of FF to furfuryl alcohol (FA) to TFA. Competing reaction routes involved decarbonylation of FF to furan (FUR) followed by hydrogenation to tetrahydrofuran (THF) or hydrogenolysis to n-butane (BU) and the hydrogenation of the carbonyl group in FF to form 2-methyl furan (mFUR) and its hydrogenation to 2-methyltetrahydrofuran (mTHF). A third competing route consisted of the nucleophilic addition of FF with ethanol and with FA to form acetals (such as 2-(diethoxymethyl)furan, FDA), which were later converted to difurfuryl ether (DFE) and tetrahydrofurfuryl ethyl ether (TFEE) as final products. Hydrogen pressure favored the production of TFA and diminished the formation of acetals, while temperature reduced the capacity of the catalyst to hydrogenate the furan ring, thus reducing TFA and increasing FA and FUR. An 80% yield to TFA was achieved with the Ni2Mg1Al catalysts after 6 h at 190 °C and 50 bar H2, but a variety of coproducts were present at low concentration. Testing of the catalysts in gas-phase hydrogenation conditions at atmospheric pressure revealed a poorer performance, with FA as the main product.

Ru-Ni Alloy Nanoparticles Loaded on N-Doped Amphiphilic Mesoporous Hollow Carbon@silica Spheres as Catalyst for the Hydrogenation of α-Pinene to cis-Pinane.

N-doped mesoporous carbon spheres (NHMC@mSiO2 ) encapsulated in silica shells were prepared by emulsion polymerization and domain-limited carbonization using ethylenediamine as the nitrogen source, and Ru-Ni alloy catalysts were prepared for the hydrogenation of α-pinene in the aqueous phase. The internal cavities of this nanomaterial are lipophilic, enhancing mass transfer and enrichment of the reactants, and the hydrophilic silica shell enhances the dispersion of the catalyst in water. N-doping allows more catalytically active metal particles to be anchored to the amphiphilic carrier, enhancing its catalytic activity and stability. In addition, a synergistic effect between Ru and Ni significantly enhances the catalytic activity. The factors influencing the hydrogenation of α-pinene were investigated, and the optimum reaction conditions were determined to be as follows: 100 °C, 1.0 MPa H2 , 3 h. The high stability and recyclability of the Ru-Ni alloy catalyst were demonstrated through cycling experiments.

Dehydrogenation and low-pressure hydrogenation properties of NaAlH4 confined in mesoporous carbon black for hydrogen storage

For hydrogen to be successfully used as an energy carrier in a new renewable energy driven economy, more efficient hydrogen storage technologies have to be found. Solid-state hydrogen storage in complex metal hydrides, such as sodium alanate (NaAlH4), is a well-researched candidate for this application. A series of NaAlH4/mesoporous carbon black composites, with high NaAlH4 content (50–90 wt%), prepared via ball milling have demonstrated significantly lower dehydrogenation temperatures with intense dehydrogenation starting at ∼373 K compared to bulk alanate's ≥ 456 K. Dehydrogenation/hydrogenation cycling experiments have demonstrated partial hydrogenation at 6 MPa H2 and 423 K. The cycling experiments combined with temperature-programmed dehydrogenation and powder X-ray diffraction have given insight into the fundamental processes driving the H2 release and uptake in the NaAlH4/carbon composites. It is established that most of the hydrogenation behavior can be attributed to the Na3AlH6 ↔ NaH transition.

Green and Efficient Acquirement of Unsaturated Ether from Direct and Selective Hydrogenation Coupling Unsaturated Aldehyde with Alcohol by Bi-Functional Al-Ni-P Heterogeneous Catalysts

In view of the industrial importance of high-grade unsaturated ether (UE) and the inconvenience of acquiring the compound, herein, a series of low-cost Al-Ni-P catalysts in robust AlPO4/Ni2P structure possessing novel bi-functional catalytic features (hydrogenation activation and acid catalysis) were innovated, and testified to be efficient for directly synthesizing UE with a superior yield up to 97% from the selective hydrogenation coupling carbonyl of unsaturated aldehyde (cinnamaldehyde or citral) with C1–C5 primary or secondary alcohol under 0.1 MPa H2 and 393 K. The integrated advantages of high efficiency, green manner and convenient operation of the present heterogeneous catalytic system gave the system potential for feasibly harvesting high-grade unsaturated ether in related fine chemical synthesis networks.

Facet-dependent Pd0-O2−-Ce3+ active site for selective hydrogenation of linoleate ester to cis oleic acid ester

Reducing the formation of trans fatty acid in vegetable oil hydrogenation process is of significance to ensure food safety. Herein, Pd0-O2−-Ce3+ active site was constructed by strong electronic interactions between Pd0 and CeO2-Polyhedrons to promote the formation of cis fatty acid. Results reveal that the abundant oxygen vacancies of CeO2 (111) facets promote the adsorption and activation of hydrogen, leading to excellent catalytic activity of Pd/CeO2-Polyhedrons. Moreover, electronic reconstructed Pd0-O2−-Ce3+ active site limits the σ-bond rotation of half-hydrogenated intermediates through enhancing π backdonation and weakening the σ-bond, contributing to the reduction of trans products. Under mild conditions (30 °C, 0.3 MPa H2, and 2 h), Pd/CeO2-Polyhedrons catalyst shows exceptional methyl oleate selectivity of 52.6% with 93.8% conversion for sunflower oil hydrogenation. The catalyst has been further extended to the selective hydrogenation to several other vegetable oils such as sunflower oil, peanut oil, soybean oil, among others, under mild conditions.

Synthesis of High-Molecular-Weight Biobased Aliphatic Polyesters by Acyclic Diene Metathesis Polymerization in Ionic Liquids.

Acyclic diene metathesis (ADMET) polymerization of an α,ω-diene monomer of bis(undec-10-enoate) with isosorbide (M1) using a RuCl2(IMesH2)(CH-2-O i Pr-C6H4) (HG2, IMesH2 = 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene) catalyst and conducted at 50 °C (in vacuo) in ionic liquids (ILs) afforded higher-molecular-weight polymers (P1, M n = 32 200-39 200) than those reported previously (M n = 5600-14700). 1-n-Butyl-3-methyl imidazolium hexafluorophosphate ([Bmim]PF6) and 1-n-hexyl-3-methyl imidazolium bis(trifluoromethanesulfonyl)imide ([Hmim]TFSI) were suitable as effective solvents among a series of imidazolium salts and the pyridinium salts. The polymerization of α,ω-diene monomers of bis(undec-10-enoate) with isomannide (M2), 1,4-cyclohexanedimethanol (M3), and 1,4-butanediol (M4) in [Bmim]PF6 and [Hmim]TFSI also afforded the higher-molecular-weight polymers. The M n values in the resultant polymers did not decrease even under the scale-up conditions (300 mg to 1.0 g scale, M1, M2, and M4) in the polymerizations in [Hmim]TFSI; the subsequent reaction of P1 with ethylene (0.8 MPa, 50 °C, and 5 h) gave oligomers (proceeded via depolymerization). Tandem hydrogenation of the resultant unsaturated polymers (P1) in a [Bmim]PF6-toluene biphasic system upon the addition of Al2O3 (1.0 MPa H2 at 50 °C) gave the corresponding saturated polymers (HP1), which waswere isolated by a phase separation in the toluene layer. The [Bmim]PF6 layer containing the ruthenium catalyst could be recycled without a decrease in the activity/selectivity of the olefin hydrogenation at least eight times.

Pd nanoparticles encapsulated in MOF boosts selective hydrogenation of biomass derived compound under mild conditions

Catalytic conversion of biomass-derived compounds into value-added chemicals or liquid fuels is of significant importance for the valorization of sustainable biomass. Currently, selective hydrogenation of typical biomass-derived 5‑hydroxymethylfurfural (HMF) to the valuable 2,5-dihydroxymethyl-tetrahydrofuran (DHMTHF) has attracted considerable interest, but still suffers from the low efficiency and harsh H2 pressure (usually 4 ∼ 8 MPa) in this process. Therefore, developing more efficient catalysts for the facile synthesis of DHMTHF from HMF under mild conditions is highly desired. Herein, small Pd nanoparticles were encapsulated in a metal–organic framework (Pd@MOF-303), and highly stabilized by the adjacent pair of N atoms of organic linkers of MOF-303. The small Pd nanoparticles were significantly efficient for HMF conversion to DHMTHF, and exhibited a yield of 95.8 % with a production rate of 85.1 h−1 under 1 MPa H2. The excellent catalytic performance was attributed to the small Pd nanoparticles which could expose more stable defective sites that were highly active and selective for this reaction.

Hydrogenation of CO2 into Formates by Ligand‐Capped Palladium Heterogeneous Catalysts

AbstractThe synthesis of two series of catalysts based on ligand‐capped supported Pd nanoparticles was carried out using a simple procedure and the resulting materials were tested in the formate synthesis. Within these series, PPh3 revealed the most appropriate stabilizing ligand while TiO2 was the most efficient support for these catalysts. The hydrogenation of CO2 was carried out under mild reaction conditions (1.8 MPa CO2, 1.8 MPa H2, 60 °C) using water as solvent and in the presence of a base, providing excellent selectivity towards formates with a TON of 1032 (TOF of 69 h−1, [HCOOK]=1.1 mol/l).

Selective Amination of Benzaldehyde over the Fine Ru Nanoparticles Anchored in NiO Catalysts

The selective amination of benzaldehyde (BZH) is one of the important industrial reactions for the production of fine chemicals. Herein, we synthesized a Ru/NiO nanocatalyst with an extremely low loading of noble metals (0.22%) via a facile ball-milling method efficient for the conversion of BZH to N-benzylidenebenzylamine (N-BDB). Compared with the benchmark im-Ru/NiO catalyst prepared via the traditional impregnation (im) method, the Ru/NiO catalyst exhibited the higher yield of N-BDB, with a full conversion of BZH and a 91.5% selectivity to N-BDB in 0.1 MPa NH3 and 2 MPa H2 pressure. After that, various parameters that influenced the catalytic performance and potential reaction pathway were investigated. In addition, the catalyst maintained high stability, which could be recycled even for five runs without obvious deactivation. Extensive characterizations verified that the H2 activation ability of Ru and the overall acidity of the Ru/NiO catalyst were improved, which should account for the superior catalytic performance. This work provides a facile strategy of catalyst synthesis for the selective production of fine chemicals.

Reactivity of Sulfur and Nitrogen Compounds of FCC Light Cycle Oil in Hydrotreating over CoMoS and NiMoS Catalysts

NiMoS and CoMoS catalysts were synthesized and applied to hydrotreating (HDT) of FCC light cycle oils (FCC-LCO) in an autoclave batch reactor at 613 K and 8.6 MPa H2. The S and N compounds in LCO were classified into four and three groups, respectively, in terms of the HDT reactivity. The individual and the competitive reactivities of the S and N compounds in the HDS and the HDN were investigated over the conventional CoMoS and NiMoS catalysts using S and N model compounds (dibenzothiophene, DBT, and carbazole, CBZ). In the HDS of DBT, both the direct desulfurization (DDS) and pre-hydrogenation pathway (HYD) were found to proceed, whereas the HYD pathway was favored for the HDN of CBZ. As a result, the NiMoS catalyst that facilitates the HYD pathway showed better activity in the HDN of LCO than the CoMoS (k = 10.20 × 10−2 vs. 1.80 × 10−2 h−1). Indeed, the HDS of LCO over the NiMoS was more favorable than that over the CoMoS catalyst (k = 4.3 × 10−1 vs. 3.6 × 10−1 h−1).