H2 Reaction Research Articles

Selective determination of collectively accelerated 12C ion bunches by neutron time-of-flight spectrometry

In this work, we investigated the possibility of selectively detecting carbon ion bunches collectively accelerated in a Luce diode by a time-of-flight spectrometry of neutrons from the threshold reaction 2H(12C,n)13N induced in Ca(OD)2 layers deposited on Mo substrates by ‘staining’ lime freshly prepared by quenching CaO in heavy water. Oxygen and calcium isotopes do not produce any interference with the analytical reaction on the carbon and proton bunches. This spectrometry confirms that 12C ions and protons are collectively accelerated at the same speed, and 12C ions are captured in this acceleration all the way from the anode to the target, regardless of the conditions of the near-anode plasma.

The global potential energy surface of the RbH2 system and dynamics studies of the H + RbH → Rb + H2 reaction

A new global potential energy surface of the ground state of the RbH2system is constructed by using the permutation invariant polynomial neural network method.In the ab initiocalculations, the aug-cc-pVQZ basis set for H, Def2-QZVPP basis set for Rb, and multi-reference configuration interaction method with Davidson correction are used. The topographical features of the new PES are discussed in detail, and no wells and barriers in the minimum energy path are found. Thereafter, specific initial-state dynamics calculations of the H + RbH (v = 0 ∼ 2,j = 0) → Rb + H2reaction are carried out based on the new PES by means of the time-dependent quantum wave packet method with a second-order split operator. The dynamics results indicate that the vibrational excitation of RbH molecules reduces and increases the reaction probability when the collision energy is below 0.4 eV and above 0.4 eV, respectively.

Infrared heated co-pyrolysis behavior of polyethylene and corn stover via optimization of secondary reactions

Infrared-fast pyrolysis (IF) has proven effective for examining the co-pyrolysis behavior of polyethylene (PE) and corn stover (CS) by optimizing secondary reactions. In this study, a fixed-bed reactor with fast infrared heating was adopted to explore the distribution of pyrolysis products and compare the product compositions generated by IF with those produced by electric-conventional slow pyrolysis (ECS). Increasing the PE ratio first increased the oil yield and then reduced it at 600 °C during the co-pyrolysis process by IF. The maximum oil yield produced by IF in PE50%-CS50% was 1.6 times the calculated yield, whereas the oil generated by ECS were roughly comparable to the calculated amount. Owing to the sluggish heating rate in ECS, the pyrolysis volatiles experienced a prolonged residence time in the high-temperature area, resulting in a severe secondary reaction and large variations in H2 and CO2 content. The highest H2 content in PE75%-CS25% was 18.09 vol%, which was 3.4 times the calculated value. The lowest CO2 content was 45.7 vol% in PE50%-CS50%, which was 27% less than predicted. During IF, The phenols, ketones, acids, aldehydes, and polyaromatic rings gradually decreased as the PE ratio increased, while the alcohol and ester content initially increased and then decreased. The alcohol reached a maximum content of 57.3% in CS50%-PE50%, while the ester reached a maximum value in PE25%-CS75%. The increased PE content produced a large number of hydrogen radicals that accelerated the hydrogenation and deoxygenation reactions of phenols and furans.

Formate-driven H2 production by whole cells of Thermoanaerobacter kivui

BackgroundIn times of global warming there is an urgent need to replace fossil fuel-based energy vectors by less carbon dioxide (CO2)-emitting alternatives. One attractive option is the use of molecular hydrogen (H2) since its combustion emits water (H2O) and not CO2. Therefore, H2 is regarded as a non-polluting fuel. The ways to produce H2 can be diverse, but steam reformation of conventional fossil fuel sources is still the main producer of H2 gas up to date. Biohydrogen production via microbes could be an alternative, environmentally friendly and renewable way of future H2 production, especially when the flexible and inexpensive C1 compound formate is used as substrate.ResultsIn this study, the versatile compound formate was used as substrate to drive H2 production by whole cells of the thermophilic acetogenic bacterium Thermoanaerobacter kivui which harbors a highly active hydrogen-dependent CO2 reductase (HDCR) to oxidize formate to H2 and CO2 and vice versa. Under optimized reaction conditions, T. kivui cells demonstrated the highest H2 production rates (qH2 = 685 mmol g−1 h−1) which were so far reported in the literature for wild-type organisms. Additionally, high yields (Y(H2/formate)) of 0.86 mol mol−1 and a hydrogen evolution rate (HER) of 999 mmol L−1 h−1 were observed. Finally, stirred-tank bioreactor experiments demonstrated the upscaling feasibility of the applied whole cell system and indicated the importance of pH control for the reaction of formate-driven H2 production.ConclusionsThe thermophilic acetogenic bacterium T. kivui is an efficient biocatalyst for the oxidation of formate to H2 (and CO2). The existing genetic tool box of acetogenic bacteria bears further potential to optimize biohydrogen production in future and to contribute to a future sustainable formate/H2 bio-economy.

Heterozygous SOD2 deletion selectively impairs SERCA function in the soleus of female mice.

The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) restores intracellular Ca2+ ([Ca2+]i) to resting levels after muscle contraction, ultimately eliciting relaxation. SERCA pumps are highly susceptible to tyrosine (T)‐nitration, impairing their ability to take up Ca2+ resulting in reduced muscle function and increased [Ca2+]i and cellular damage. The mitochondrial antioxidant enzyme, superoxide dismutase 2 (SOD2), converts superoxide radicals into less reactive H2O2. Heterozygous deletion of SOD2 (Sod2 +/−) in mice increases mitochondrial oxidative stress; however, the consequences of reduced SOD2 expression in skeletal and cardiac muscle, specifically the effect on SERCA pumps, has yet to be investigated. We obtained soleus, extensor digitorum longus (EDL), and left ventricle (LV) muscles from 6 to 7 month‐old wild‐type (WT) and Sod2 +/− female C57BL/6J mice. Ca2+‐dependent SERCA activity assays were performed to assess SERCA function. Western blotting was conducted to examine the protein content of SERCA, phospholamban, and sarcolipin; and immunoprecipitation experiments were done to assess SERCA2a‐ and SERCA1a‐specific T‐nitration. Heterozygous SOD2 deletion did not alter SERCA1a or SERCA2a expression in the soleus or LV but reduced SERCA2a in the EDL compared with WT, though this was not statistically significant. Soleus muscles from Sod2 +/− mice showed a significant reduction in SERCA’s apparent affinity for Ca2+ when compared to WT, corresponding with significantly elevated SERCA2a T‐nitration in the soleus. No effect was seen in the EDL or the LV. This is the first study to investigate the effects of SOD2 deficiency on muscle SERCA function and shows that it selectively impairs SERCA function in the soleus.

Plasma-Assisted Dinitrogen Activation via Dual Platinum Cluster Catalysis: A Strategy for Ammonia Synthesis under Mild Conditions

Plasma-Assisted Dinitrogen Activation via Dual Platinum Cluster Catalysis: A Strategy for Ammonia Synthesis under Mild Conditions

Nickel Nanoparticles Encapsulated in Nitrogen‐Doped Carbon Nanofibers as Excellent Bifunctional Catalyst for Hydrogen and Oxygen Evolution Processes

AbstractThe potential of nitrogen‐doped carbon nanofibers with encapsulated Ni nanoparticles as a bifunctional catalyst in H2 and O2 evolution reactions (HER and OER, respectively) was studied. The proposed heterostructure is fabricated via a facile chemical vapor deposition on Ni supported on graphitic carbon nitride (GCN) as a precursor. HER was an effect of photocatalytic water splitting and catalytic dehydrogenation of lactic acid used as sacrificial electron donor. However, photocatalysis played the dominant role in the acceleration of the reaction rate which was 17 times and 330 times higher in respect to the sample prior the CVD and to pristine GCN, respectively. The catalyst exhibited boosted electrocatalytic activity in OER and outstanding stability in respect to RuO2 in alkaline medium. The overpotentials calculated from linear sweep voltammetry at 10 mA cm−2 is ∼383 mV for the fabricated electrocatalyst in respect to 490 mV for the RuO2 and Tafel slope is calculated to be 106 mV dec−1 in comparison to 136 mV dec−1 for the reference which is above the state‐of the‐art bifunctional catalysts reported to date. The results reveal that the catalytic processes were boosted due to several key effects such as enhanced visible light absorption, better charge carriers transfer and separation, increased free charge carrier concentration and higher reducing ability of electrons.

Cu-Co nanoparticles supported on nitrogen-doped carbon: An efficient catalyst for hydrogenation of 5-hydroxymethylfurfural into 2,5-bis(hydroxymethyl)furan

Production of the 2,5-Bis(hydroxymethyl)furan (BHMF) has important scientific value and strategic significance for the development of new biodegradable polyester materials. Herein, Cu-Co/NC composites containing bimetallic nanoparticles in nitrogen-doped carbon were produced by the calcination of zeolitic imidazolate frameworks (ZIFs). They featured a cubic Cu-Co core and a porous structure derived from the ZIFs. The surface morphology, surface area, and composition of the catalysts were analyzed by scanning electron microscopy (SEM), transmission electron microscope (TEM), thermogravimetric (TG) analysis, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), CO2-temperature program desorption (CO2-TPD), and N2 adsorption-desorption isotherms. A conversion of 93.7% of 5-hydroxymethylfurfural (HMF) with a BHMF selectivity of 92.4% was achieved using the Cu0.04Co1/NC-450 catalyst at a relatively low reaction temperature and H2 pressure. This outstanding catalytic performance was ascribed to the high dispersion of Co nanoparticles in the NC framework, forming Co-Nx species. We found that the synergistic catalysis of Cu-Co sites due to electron transfer contributed to the increase in the BHMF selectivity during HMF hydrogenation. The intensity of the XRD peaks corresponding to metallic Co decreased as the calcination temperature increases, which results in agglomeration of Co nanoparticles (NPs), and reduces the catalytic activity in HMF hydrogenation. Additionally, the conversion of HMF during hydrogenation remained stable after using Cu0.04Co1/NC-450 for ten cycles.

Efficient hydrodeoxygenation of lignocellulose derivative oxygenates to aviation fuel range alkanes using Pd-Ru/hydroxyapatite catalysts

Bimetallic Pd-Ru/ hydroxyapatite (HAP) catalysts were developed together with Zirconium phosphate (ZrP) to prepare aviation fuel range hydrocarbons by one-pot HDO from lignocellulose-derived C15 oxygenate. The effects of the catalyst composition, reaction time, initial H2 pressure and reaction temperature on the HDO were explored. 84.24% C8-C15 alkanes could be obtained by Pd0.6-Ru1.8/HAP at 150 °C, 4 MPa H2. The HDO pathway and the stability of the catalyst were also investigated. To explore the synergy of bimetals and the efficiency of the catalysts, a series of characterizations were conducted. The results verified that the bimetallic catalyst had a better adsorption capacity for the substrate, and the ruthenium external electron density raised due to the introduction of palladium, thereby enhancing the hydrodeoxygenation activity of the catalyst.

In-situ TEM investigation of dislocation loop reaction and irradiation hardening in H2+-He+ dual-beam irradiated Mo

• Irradiation can directly cause the formation of 1/2<111> loops and <100> loops. • Irradiation can directly induce 1/2<111>loop to transform into <100> loop. • Two 1/2<111> loops react to form <100> loop without strict size similarity condition. • Yield strength increment caused by irradiation-induced loops is analyzed. • Loop evolution and its relationship with irradiation dose are established. Through in-situ TEM observation during 30 keV H 2 + -He + dual-beam irradiation at 723 K, the reaction and transformation of dislocation loops in pure Mo were investigated, especially for <100> loops. Irradiation could directly cause the formation of 1/2<111> loops and <100> loops, but 1/2<111> loops were dominant. In-situ observation confirmed the formation mechanism of <100> loops, including direct irradiation induced mechanism, 1/2<111> loop direct conversion mechanism, and reaction mechanism of two 1/2<111> loops. Meanwhile, the reaction of two 1/2<111> loops to produce <100> loop should not require the strict size similarity condition. The reaction between 1/2<111> loops could also produce 1/2<111> loop, which was essentially a process in which one loop absorbed another one. The yield strength increment caused by irradiation-induced loops was analyzed, and its saturation value reached 0.48 GPa at 0.06 dpa. Compared with single He + irradiation, the number density and average diameter of loops increased significantly and more serious damage was caused under the synergistic effect of hydrogen and helium. The mechanism based on in-situ experimental observation was discussed in depth. Graphical Abstract .

Catalytic Hydrodeoxygenation of Guaiacol to Cyclohexanol over Bimetallic NiMo-MOF-Derived Catalysts

Lignin is an attractive renewable source of aromatics with a low effective hydrogen to carbon ratio (H/Ceff). The catalytic hydrodeoxygenation (HDO) of lignin-derived model compounds is a key strategy for lignin upgrading. In this work, the HDO of guaiacol, a typical lignin-derived compound, was carried out over metal–organic framework (MOF)-derived Ni-based catalysts. A monometallic Ni-MOF catalyst and different ratios of bimetallic NiMo-MOF catalysts were synthesized by a hydrothermal process, followed by a carbonization process. Among these catalysts, Ni3Mo1@C exhibited an excellent catalytic performance, affording a guaiacol conversion of 98.8% and a cyclohexanol selectivity of 66.8% at 240 °C and 2 MPa H2 for 4 h. The addition of Mo decreased the particle size of the spherical structure and improved the dispersion of metal particles. The synergistic effect between Ni and Mo was confirmed by various means, including ICP, XRD, SEM, TEM, and NH3-TPD analyses. In addition, the effect of the reaction temperature, time, and H2 pressure during the HDO process is discussed in detail.

Thermal and chemical analysis on the hetero-/homogeneous combustion characteristics of H2/Air mixture in a micro channel with catalyst segmentation

The heterogeneous-homogeneous combustion characteristics of premixed H2/Air mixture in a micro combustor with 2 mm platinum (Pt) catalyst segmentation are investigated by numerical simulation. The detailed chemical reaction mechanisms of gas-phase reaction and surface reaction of H2 are employed in a 2D CFD model by the verification. The characteristics in the catalytic combustor, such as temperature distribution, species concentration, kinetics reaction rate and heat transfer, are examined by varying inlet flow velocities. There is an interesting fact that an obvious demarcation line splits the channel into two regions at high velocities, which are dominated by heterogeneous reaction (Htr) and homogeneous reaction (Hr). In addition, there is a coupling heterogeneous-homogeneous reaction (HHr) in the 2 mm downstream of the catalytic region. These should be thoroughly deliberated using thermal and chemical analyses to determine that the gaseous flame is against the Htr in the catalytic combustor. The results can be shown that the heat flux into the upstream catalytic wall is primarily due to exothermicity induced by Htr. A low amount of heat feedback via the solid wall to inlet wall which is released by Hr. The heat fluxes from the gas–solid interface preheat the fresh gaseous mixture in the channel, thereby promoting the occurrence of Hr, increasing the heat release rate and kinetic reaction rate of Hr. Moreover, heat feedback from the heat release of Hr through the solid wall increases the reaction rates of Htr. The hydrogen conversion rate is improved by the effect of Htr in the catalytic combustor. In summary, the effect of introducing catalytic surface to induce the Htr could be well suitable for micro combustion schemes.

Selective Catalytic Oxidation of Methane to Methanol in Aqueous Medium over Copper Cations Promoted by Atomically Dispersed Rhodium on TiO2

AbstractDirect conversion of methane into value‐added chemicals, such as methanol under mild conditions, is a promising route for industrial applications. In this work, atomically dispersed Rh on TiO2 suspended in an aqueous solution was used for the oxidation of methane to methanol. Promoted by copper cations (as co‐catalyst) in solution, the catalysts exhibited high activity and selectivity for the production of methanol using molecular oxygen with the presence of carbon monoxide at 150 °C with a reaction pressure of 31 bar. Millimole level yields of methanol were reached with the selectivity higher than 99 % using the Rh/TiO2 catalysts with the promotion of the copper cation. CO was the reductive agent to generate H2 from H2O, which led to the formation of H2O2 through the reaction of H2 and O2. Atomically dispersed Rh activated the C−H bond in CH4 and catalyzed the oxidation using H2O2. Copper cations maintained the low‐valence state of Rh. Moreover, copper acted as a scavenger for suppressing the overoxidation, thus leading to the high selectivity of methanol.

Selective Catalytic Oxidation of Methane to Methanol in Aqueous Medium over Copper Cations Promoted by Atomically Dispersed Rhodium on TiO2.

Direct conversion of methane into value-added chemicals, such as methanol under mild conditions, is a promising route for industrial applications. In this work, atomically dispersed Rh on TiO2 suspended in an aqueous solution was used for the oxidation of methane to methanol. Promoted by copper cations (as co-catalyst) in solution, the catalysts exhibited high activity and selectivity for the production of methanol using molecular oxygen with the presence of carbon monoxide at 150 °C with a reaction pressure of 31 bar. Millimole level yields of methanol were reached with the selectivity higher than 99 % using the Rh/TiO2 catalysts with the promotion of the copper cation. CO was the reductive agent to generate H2 from H2 O, which led to the formation of H2 O2 through the reaction of H2 and O2 . Atomically dispersed Rh activated the C-H bond in CH4 and catalyzed the oxidation using H2 O2 . Copper cations maintained the low-valence state of Rh. Moreover, copper acted as a scavenger for suppressing the overoxidation, thus leading to the high selectivity of methanol.

Numerical study of a porous open channel for the proton-exchange membrane fuel cell

The operation of a fuel cell (PEMFC) is associated with severe problems related to individual components' local power density and durability. The problem arises from the unsatisfactory distribution of the H2 and O2 reaction components and the high flow resistance. To find an answer to the problem posed, we tested nine variants of open anode/cathode channels dedicated to subsequent 3D printing. We have compared the obtained current-voltage characteristic curves with the experimental data of the fuel cell for which the new channels were dedicated. Each of the newly designed open flow channels had better current characteristics. Subsequently, we have compared selected cell properties between the best variants from the section. The final shape of the open channel ensured a high value of the current flux and local power density in the entire operating range of the fuel cell. Also, it generated low flow resistance allows for building a stack of cells.

Demonstration of a high-efficiency carbon dioxide capture and methanation system with heat/material integration for power-to-gas and zero carbon dioxide emissions in flue gasses

Carbon dioxide (CO2) capture and methanation are important methods for realizing both power-to-gas and zero CO2 emissions. However, the technology needs to be improved to solve implementation barriers such as energy efficiency, compactness, economics, and CO2 source flexibility, especially for CO2 derived from fuel combustion.The present report describes the development of a high-efficiency integrated system to separate CO2 from flue gas with a high recovery rate and convert it to high-quality CH4 using in-system heat/material integration.A carbon recycling system with a throughput of 5.1-kW CH4 (LHV basis) was integrated with CO2 adsorbers using zeolite and catalytic methanation reactors. System efficiency, defined as the energy ratio of output CH4 and H2 against the sum of input H2 and power for system operation, was then evaluated using exhaust gas from a combustion furnace with a CO2 concentration of 9%. In general, a decrease in the energy required for system operations, such as gas treatment, CO2 separation, and auxiliary machines, improves efficiency. Two challenges were encountered during the study: reduction in CO2 separation energy by implementation of heat/material management using a H2 reactant as a sweep gas and the reaction heat of methanation, and a reduction in gas compression energy by conducting the methanation reaction under the lowest possible pressure. The results indicated that the CO2 conversion rate was greater than 99% under a pressure of 225 kPa-G, and the only energy consumed was by the oil pump for cooling the reactors. Due to the use of H2 sweep gas and methanation heat recovery, the CO2 recovery rate was also greater than 99%, and the additional energy consumption (1.8 GJ/t-CO2) was due to vacuum pumps. In addition, the system achieved an efficiency greater than 70% (LHV basis), while maintaining both a CO2 recovery rate and a conversion of greater than 99%. Because the energy for dehydration of the exhaust gas was the most significant portion of the total system operational energy, further improvement of the system efficiency is thought to be possible by reducing the energy required for dehydration.

Pd loading, Mn+ (n=1, 2, 3) metal ions doped TiO2 nanosheets for enhanced photocatalytic H2 production and reaction mechanism

Pd nanoparticles (NPs) loading, main group metal ions doped TiO 2 nanosheets were prepared by a hydrothermal method, followed by photo-deposition of Pd. The samples were characterized, and their photocatalytic hydrogen production activities were tested in a methanol aqueous solution. The effects of cationic charge, radius and concentration of the doping ions (Na + , K + , Mg 2+ , Al 3+ ) on the photocatalytic activities were investigated systematically. The photocatalytic reaction mechanism was discussed by considering the three aspects: specific surface area, light absorption and charge transfer/separation. The results show that the cation dopings significantly increased the photocatalytic activities of the TiO 2 nanosheets, which may be attributed to the enhanced UV-vis light absorption and accelerated charge transfer/separation of the catalysts. Particularly, the Pd/0.2%K + -TiO 2 possesses the highest photocatalytic H 2 production activity (76.6 μmol h −1 ), which is more than twofold higher than that of the undoped Pd/TiO 2 . The apparent quantum efficiency of hydrogen evolution system reaches 3.0% at 365 nm. The high activity of the Pd/K + -TiO 2 may be attributed to the lower electronegativity of K + , caused by the lower cationic charge or the larger cationic radius, compared to Na + , Mg 2+ and Al 3+ . The doping metal cations with higher electronegativity may compete electrons with H + , which eventually partly depressed the reduction of H + to H 2 . • Pd loading main group metal ions doped TiO 2 nanosheets were synthesized. • Effects of cation charge, radius and content on photocatalytic activity were explored. • Photocatalytic H 2 evolution mechanism was discussed based on experimental results. • 0.2% K + doping increased the H 2 production efficiency by more than two times. • Enhanced light absorption and charge transfer due to M + doping led to higher activity.

Methylene Blue Dye as Photosensitizer for Scavenger-Less Water Photo Splitting: New Insight in Green Hydrogen Technology.

In this study, hydrogen generation was performed by utilizing methylene blue dye as visible-light photosensitizer while the used catalyst is working as a transfer bridge for the electrons to H+/H2 reaction. Silica NPs-incorporated TiO2 nanofibers, which have a more significant band gap and longer electrons lifetime compared to pristine TiO2, were used as a catalyst. The nanofibers were prepared by electrospinning of amorphous SiO2 NPs/titanium isopropoxide/poly (vinyl acetate)/N, N-dimethylformamide colloid. Physicochemical characterizations confirmed the preparation of well morphology SiO2–TiO2 nanofibers with a bandgap energy of 3.265 eV. Under visible light radiation, hydrogen and oxygen were obtained in good stoichiometric rates (9.5 and 4.7 mL/min/gcat, respectively) without any considerable change in the dye concentration, which proves the successful exploitation of the dye as a photosensitizer. Under UV irradiation, SiO2 NPs incorporation distinctly enhanced the dye photodegradation, as around 91 and 94% removal efficiency were obtained from TiO2 nanofibers containing 4 and 6 wt% of the used dopant, respectively, within 60 min.

Tubular g-C3N4 coupled with lanthanide oxides Yb2O3 as a novel bifunctional photocatalyst：Enhanced photocatalytic NO removal and H2 evolution, dual regulation and reaction pathway

The modification of graphite carbonitride (g-C3N4) is beneficial to increase its specific surface area and high quantum efficiency, thus improving its activity. Herein, the Yb2O3/g-C3N4 composites were adjusted through dual regulation synergistically (nanostructure design of g-C3N4 and addition of lanthanide oxides Yb2O3) to improve the photocatalytic performance of hydrogen production and NO removal simultaneously. The as-prepared 1% Yb2O3/tubular g-C3N4 could efficiently promote the photocatalytic hydrogen evolution (4071.763 μmol·g−1·h−1) and NO removal performance (54.20%), which was approximately 8.85 times and 32.01% higher respectively than that of bulk g-C3N4 prepared by melamine (g-C3N4-M). The formation process of·O2- and·OH radicals and the oxidation process of NO had been systematically studied through ESR and in-situ DRIFTS, which proved that the coupling of tubular g-C3N4 with Yb2O3 had a positive effect. This work provided a novel strategy for dual regulation (adjust morphology and metal oxide introduction) synergistically design of bifunctional photocatalysts to enhance H2 production and NO removal simultaneously.

Catalytic Hydrodesulfurization of a Spent Tire Pyrolysis Oil Distillate over a Ni–Mo Catalyst

This paper reports an experimental investigation into catalytic hydrodesulfurization of a spent tire pyrolysis oil distillate over a Ni–Mo catalyst. The desulfurization efficacy of the catalyst was evaluated over a range of reaction times (1–36 h), temperatures (300–375 °C), pressures (1–4 MPa), H2 concentrations (16.7–33.3% v/v), and reactive gas flow rates (H2 in N2, 45–90 mL min–1). Increasing temperature, pressure, or H2 concentration increased sulfur removal to a maximum of 99.9% w/w at 350 °C, 4 MPa, and 45 mL min–1 33.3% v/v H2. The treatment not only effectively removed sulfur but also reduced oxygenates, nitrogen-bearing compounds, and alkenes. The role of the Ni–Mo catalyst changed from adsorbing sulfur to catalyzing hydrodesulfurization as it was sulfided to Ni3S2 and MoS2. Full catalyst reduction only slightly increased the initial desulfurization activity but had an insignificant influence on subsequent sulfur removal as both the oxidized and reduced Ni and Mo forms could be sulfided to Ni3S2 and MoS2.