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The absolute vapor pressures of three amino-alcohols were measured using the transpiration method. The consistent set of standard molar enthalpies of vaporization for eighteen amino-alcohols was evaluated using empirical and structure–property correlations. The averaged values of vaporization enthalpies were recommended as reliable benchmark properties for the heat management of CO2 capture technologies. Centerpiece approach based on the group-additivity principles was developed toward amino-alcohols. Graphic abstract

Co-PMo catalysts were prepared from the 12-molybdophosphoric heteropolyacid and cobalt citrate on the base of freshly-synthesized alumina and mixed MCM-41-Al2O3 material. Carriers and catalysts were characterized by the following techniques: X-ray powder diffraction, low-temperature N2 adsorption, NH3-TPD, Raman spectroscopy, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. Prepared catalysts were tested in hydrodesulfurization of dibenzothiophene and hydrogenation of naphthalene. It has been shown that mesoporous silica incorporation into alumina can improve morphological properties of the CoMoS active phase as well as the overall HDT activity.

Decalin dehydrogenation for efficient hydrogen production over platinum catalysts supported on different types of silica was studied. The catalytic properties of the prepared catalysts were tested under conditions of a flow installation. It was found that from a thermodynamic point of view, high temperatures will favor dehydrogenation, and low temperatures will favor the isomerization of cis-decalin to trans-decalin. It negatively affects the rate of decalin dehydrogenation; therefore, kinetic control is required. It was shown that the catalysts supported on mesoporous silica MCM-48 and SBA-15 showed a significantly higher catalytic activity during decalin dehydrogenation compared to catalysts supported on amorphous SiO2. The high surface area and small pore size of these supports positively affect Pt particles’ dispersion and result in the production of high-active catalysts for dehydrogenation of decalin to naphthalene. The maximum decalin conversion was observed over the 2% Pt/MCM-48 catalyst at a pressure of 0.5 MPa, a 325 °C temperature, and an LHSV of 20 h−1. This study provides a rationale for the proper support selection for efficient utilization of decalin as a LOHC.

The methoxy-, hydroxy-, and carbonyl-substituted benzenes are the simplest fragments from the lignin separation feedstocks. Extensive experimental thermochemical studies of these compounds were car...

Indole and methylindole are heterocyclic aromatics, which can be hydrogenated and used for hydrogen storage. A huge advantage of heterocyclic components compared to homocyclic aromatics is the lowe...

The composite material on the base of Al2O3 and SAPO-11 was prepared with a various concentration on SAPO-11 and investigated as a carrier of bifunctional Pt-based catalyst for n-alkanes hydroisomerization. The Al2O3-SAPO-11 composite material with an optimal composition and acidic properties was used to prepare bifunctional catalysts with different hydrogenation/dehydrogenation sites. The effectiveness of the Pt, Pd, Ni and CoMoS active sites of bifunctional catalysts supported on the composite Al2O3-SAPO-11 carrier were investigated and compared in n-hexadecane hydroisomerization. Synthesized materials were investigated using X-ray powder diffraction, scanning electronic and high-resolution transition electronic microscopies, N2 physisorption, NH3-TPD and pyridine-FTIR spectroscopy. A CoMoS active phase was studied as hydrogenation/dehydrogenation hydrogenated-dehydrogenated active sites of bifunctional hydroisomerization catalysts.

The storage of hydrogen is the key technology for a sustainable future. We developed an in silico procedure, which is based on the combination of experimental and quantum-chemical methods. This method was used to evaluate energetic parameters for hydrogenation/dehydrogenation reactions of various pyrazine derivatives as a seminal liquid organic hydrogen carriers (LOHC), that are involved in the hydrogen storage technologies. With this in silico tool, the tempo of the reliable search for suitable LOHC candidates will accelerate dramatically, leading to the design and development of efficient materials for various niche applications.

Methoxy-substituted benzenes are the simplest fragments from the lignin separation feedstock. Extensive experimental thermochemical studies of these compounds were carried out, including vapor pressure measurements, combustion and differential scanning calorimetry. These data were evaluated using empirical, semi-empirical and quantum chemical methods. The consistent sets of evaluated thermodynamic data were used to design the method for predicting enthalpies of vaporisation and enthalpies of formation of di- and tri-substituted benzenes. It has been found that the agglomeration of substituents on the benzene ring has dramatic consequences for the energetics of the molecule (in terms of the enthalpy of formation), as well as for the energetics of intermolecular interactions (in terms of the enthalpy of vaporisation). These observations are essential to reliably assess the energetics of the molecules that appear in reaction products of lignin transformations in value-adding chemicals and materials.

Mesoporous ruthenium catalysts (0.74–3.06 wt%) based on ordered Mobil Composition of Matter No. 41 (MCM-41) silica arrays on aluminosilicate halloysite nanotubes (HNTs), as well as HNT-based counterparts, were synthesized and tested in benzene hydrogenation. The structure of HNT core-shell silica composite-supported Ru catalysts were investigated by transmission electron microscopy (TEM), X-ray fluorescence (XRF) and temperature-programmed reduction (TPR-H2). The textural characteristics were specified by low-temperature nitrogen adsorption/desorption. The catalytic evaluation of Ru nanoparticles supported on both the pristine HNTs and MCM-41/HNT composite in benzene hydrogenation was carried out in a Parr multiple reactor system with batch stirred reactors (autoclaves) at 80 °C, a hydrogen pressure of 3.0 MPa and a hydrogen/benzene molar ratio of 3.3. Due to its hierarchical structure and high specific surface area, the MCM-41/HNT composite provided the uniform distribution and stabilization of Ru nanoparticles (NPs) resulted in the higher specific activity and stability as compared with the HNT-based counterpart. The highest specific activity (5594 h−1) along with deep benzene hydrogenation to cyclohexane was achieved for the Ru/MCM-41/HNT catalyst with a low metal content.

Glycerol (and activated forms such as epichlorohydrin) provide a versatile substrate for the design and synthesis of new, bio-derived compounds that can have uses in key contemporary applications such as CO2 capture, plastics recycling, and green chemistry in general. Upon etherification of one or more alcohols the glycerol skeleton, the thermophysical properties of the resultant substances change dramatically compared to glycerol. Most notably, the viscosity of glycerol-derived diethers and triethers is reduced by 2–3 orders of magnitude, however, this also corresponds to increased volatility. Determining properties of these new compounds is a key consideration for engineering process design. Here, for the first time we report a comprehensive study on the vapor pressures, heat capacities, and enthalpies of vaporization of symmetric 1,3-diethers of glycerol and provide a group additivity model for estimating the enthalpies of vaporization. The properties of these glycerol-derived solvents are compared to other compounds with similar structures.

Reactivation of industrial CoMo/Al2O3 hydrotreating (HDT) catalysts was studied. A spent catalyst was used in the ULSD production for about 2.5 years. It was oxidatively regenerated and rejuvenated by organic acids (citric and thioglycolic), glycols (ethylene and triethylene), and dimethylsulfoxide solutions. All solids were characterized by the elemental analysis, N2 physisorption, X-ray powder diffraction, thermogravimetric analysis, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Changes in the active phase composition and morphology during the CoMo/Al2O3 HDT catalyst operation, regeneration and rejuvenation were shown. The rejuvenated catalysts were tested in hydrodesulfurization (HDS) of dibenzothiophene and hydrogenation (HYD) of naphthalene. It was found that oxidative regeneration allowed restoring about 70–85% rel. of initial activity. Rejuvenation with organic chemicals resulted in the complete restoration of HDS and HYD activities. Resulting catalytic activity of the reactivated catalysts depended on the properties of the formed active phase species. These correlations are discussed in the study.

Amino-alcohols are considered for sustainable hydrogen storage systems based on catalytic peptide formation. Experimental and theoretical thermochemical studies of amino-alcohols have been performed, including vapour pressure measurements, combustion calorimetry, and quantum-chemical calculations. The standard molar enthalpies of vaporization of amino-alcohols were calculated from the temperature dependence of the vapour pressures measured by the transpiration method. Energies of combustion for six amino-alcohols were measured using the high-precision combustion calorimetry. The available in the literature primary data on vapour pressures, enthalpies of vaporization, and enthalpies of formation of amino-alcohols were collected and evaluated. The experimental standard molar gas-phase enthalpies of formation of amino-alcohols were derived from the evaluated results. The high-level G3B3, G3MP2, and G4 quantum-chemical methods were used to establish consistency of the experimental and theoretical results. The surprisingly low enthalpy of reaction of the reversible dehydrogenation of 2-amino-ethanol, calculated from the experimental data, makes this liquid organic hydrogen carrier system (LOHC) promising for further optimization and development.

The absolute vapour pressures of three amino-alcohols were measured using the transpiration method. The consistent set of standard molar enthalpies of vaporization for eighteen amino-alcohols was evaluated using empirical and structure–property correlations. Correlation of vaporization enthalpies with normal boiling temperatures was established. Vaporization enthalpies of amino-alcohols obey the group-additivity rules. The averaged values of vaporization enthalpies were recommended as reliable benchmark properties for the heat management of CO2 capture technologies.

One of the promising directions for accumulating hydrogen is its binding into a liquid organic hydrogen carrier (LOHC). In this concept, a LOHC is loaded with hydrogen (hydrogenation) during production and then discharged again (dehydrogenation) when the hydrogen is needed. Biphenyl is an interesting option as potential LOHC due to its reasonable storage capacity. This paper deals with the experimental chemical equilibrium study and a detailed analysis of the biphenyl hydrogenation reactions. We evaluated the consistent set of vapour pressures and standard molar thermodynamic properties of biphenyl derivatives with help of complementary vapour pressure measurements, and empirical and quantum-chemical calculations. The chemical equilibrium constants of hydrogenation-dehydrogenation and thermodynamic characteristics for the biphenyl system were determined.

This work contributes to our primary interest in applications of experimental and computational thermochemistry methods for providing the basic data required in chemical-process design. Pyrazine derivatives are considered as a seminal liquid organic hydrogen carriers. The standard molar enthalpies of vaporisation/sublimation of pyrazine derivatives were derived from the vapour pressure temperature dependences measured by the static and transpiration method. Enthalpies of fusion of the solid compounds were measured using DSC. Thermodynamic data on solid–gas, liquid–gas, and solid–liquid phase transitions available in the literature were collected and combined with own experimental results. We have evaluated and recommended the set of vaporisation and formation enthalpies of pyrazine derivatives at 298.15 K as the reliable benchmark properties for further thermochemical calculations. Gas phase molar enthalpies of formation of pyrazine derivatives calculated by the high-level quantum-chemical method G4 were in agreement with the recommended experimental data. Compilation of experimental and theoretical results derived in this work is useful for optimisation of hydrogenation/dehydrogenation reactions involved in the hydrogen storage technologies.

CoPMo/Al2O3 catalysts were prepared using H3PMo12O40 and Co complexes with citric acid (CA) or non-complexing organic additives such as ethylene glycol (EG), diethylene glycol, triethylene glycol (TEG), glycerol, and a mixture of EG and CA. The catalysts were characterized by low-temperature N2 adsorption, Raman spectroscopy, thermogravimetric analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The prepared samples were tested in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The addition of either CA or glycols led to several beneficial effects such as weakening of the slab-support interaction at enhancing the promotion degree, dispersion and stacking number of the CoMoS species. It has been shown that the promotion degree of CoMoS edges increased with a pore volume gain by the additive-impregnated catalysts after their sulfidation. Catalysts with CA, TEG or the EG-CA mixture demonstrated higher activity in DBT HDS. Probable reasons for the found relationships are discussed.

Vanillin and its isomers are a promising biobased building blocks for monomer synthesis. Extensive experimental thermochemical studies of these compounds have been carried out, including combustion calorimetry, vapor pressure measurements, and differential scanning calorimetry. We have collected available primary experimental results on enthalpies of formation and vapour pressures as well as on phase transitions liquid–gas, liquid–solid, crystal-liquid. These data were evaluated using empirical, semi-empirical and quantum chemical methods. The consistent sets of evaluated thermodynamic data were used to design the method for predicting enthalpies of vaporization and enthalpies of formation of di- and tri-substituted benzenes. It is expected that parameters and pairwise interactions will be transferable to predict the thermochemical properties of poly-methoxy-substituted and poly-hydroxy-substituted benzenes that appear in reaction products of lignin transformations in the value-adding chemicals and materials.

Bifunctional catalysts on the base of transition metal sulfides (CoMoS and NiWS) and platinum as noble metal were synthesized via wetness impregnation of freshly synthesized Al2O3-SAPO-11 composites, supported with favorable acidic properties. The physical-chemical properties of the prepared materials were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), low-temperature N2 adsorption and high resolution transmission electron microscopy (HR TEM) methods. Catalytic properties were studied in n-hexadecane isomerization using a fixed-bed flow reactor. The catalytic poisons tolerance of transition metal sulfides (TMS)- and Pt-catalysts has been studied for sulfur and nitrogen, with the amount of 10–100 ppm addition to feedstock. TMS-catalysts show good stability during sulfur-containing feedstock processing, whereas Pt-catalyst loses much of its isomerization activity. Nitrogen-containing compounds in the feedstock has a significant impact on the catalytic activity of both TMS and Pt-based catalysts.

Effects of activated carbon in a carbon-coated alumina (CCA) support, active phase morphology and its composition of Ni 6 -PW 12 S/C x /Al 2 O 3 catalysts in hydrotreating of model compounds were studied. The catalysts were synthesized using 12-tungstophosphoric heteropolyacid, nickel citrate and CCA and characterized with multiple methods: N 2 physisorption, X-ray powder diffraction, H 2 temperature programmed reduction, temperature-programmed desorption of ammonia, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The catalytic properties were determined using a fixed-bed microreactor in hydrotreating of dibenzothiophene, naphthalene and quinoline. It was found that with the increase of carbon content in the CCA up to 5 wt.%, reducible reactivity, sulphidation degree, average length and stacking number of WS 2 crystallites in the catalysts increased. Observed changes can be explained by weakening interaction between metal oxide species and carbon-coated support. Full promotion of the NiWS edges by nickel was achieved in the catalysts supported on the CCA with carbon content equal 0.3 wt.% and more. Activities of the catalysts in dibenzothiophene hydrodesulphurization, naphthalene hydrogenation and quinoline hydrodenitrogenation were essentially depended on the carbon content in the CCA-support. Ni 6 -PW 12 S/C 1 /Al 2 O 3 catalyst showed maximal conversions of the substrates in studied reactions. This result was achieved due to an optimal balance between turnover frequency value of the active sites and their content.

Genesis of alumina supported hydrotreating (HDT) catalysts prepared with the use of decamolybdodicobaltate heteropolyanion (Co2Mo10HPA) and cobalt citrate during their sulfidation processes and deactivation in diesel HDT has been investigated. The sulfidation stage was studied for two procedures: gas phase sulfidation by H2S/H2 and liquid phase treatment by a mixture of dimethyldisulfide in diesel at various temperatures and durations. The catalysts have been studied by N2 adsorption, thermogravimetric analysis, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy methods. The catalysts were tested in HDT of mixture of 70 wt.% straight run gas oil with 16 wt.% light cycle oil and 14 wt.% light coker gas oil. Mechanisms of the active phase formation in the course of gas and liquid phase sulfidation processes have been established. It was found that gas phase sulfidation led to formation of the CoMoS active phase with higher cobalt content comparing to liquid sulfidation of the catalyst and initial activity of the gas phase treated catalysts in diesel HDT was also higher than catalysts subjected to liquid sulfidation. Catalytic examination after accelerated deactivation conditions showed that the liquid phase sulfided sample was more resistant to the deactivation. Probably it is due to stabilization of active phase particles by coke formed intensively during liquid phase sulfidation. The results were discussed using the recently developed concept of interlayer dynamics of the active sites of the CoMoS phase.

The effect of Co/Mo ratio in the CoMo/Al2O3 hydrotreating catalysts prepared by simultaneous using of the decamolybdodicobaltate heteropolyacid (Со2Мо10HPA) and cobalt citrate was investigated. Synthesized catalysts were characterized by Raman spectroscopy, N2 adsorption, XRD, XPS, HRTEM techniques and were examined in the model reaction of 4,6-dimethyldibenzothiophene (4,6-DMDBT) HDS, in hydrotreating of straight-run gas oil (SRGO) and mixture of 80 vol.% SRGO with 20 vol.% light coker gas oil (LCGO). It was established that Co/Mo ratio in the catalysts significantly influences on the structure of CoMoS phase of type II and catalytic activity. Catalysts with λ = Co/(Co + Mo) = 0.35 had maximal activities in 4,6-DMDBT HDS and diesel HDT and showed the best stability. Increase of the Co/Mo ratio led to simultaneous growing of both average length and stacking number of CoMoS multilayer active phase of the catalysts. Average length increased from 3.0 to 4.0 nm, average staking number increased from 1.4 to 1.6. It was found out that catalysts activity decreased within Co/Mo ratio λ from 0.35 to 0.45. Analysis of textural properties of the catalysts, active phase morphology, phase composition and catalytic activities allowed us to suppose that with increase of Co/Mo ratio blocking the mesopores by sulfides of the active components and by coke species with formation of new micropores would take place. The activity of the best prepared CoMo/Al2O3 catalyst was competitive with the activity of the well-known commercial catalysts for ultra-low sulfur diesel in hydrotreating of SRGO or mixture of SRGO with LCGO.