Conventional Hydrogenation Research Articles

Biosynthetic fuels: A marriage of renewable resources and chemical thermodynamics

Terpenes represent a highly diverse group of natural products with wide applications. Terpenoid structures can be derived from different renewable sources and utilized as fuels. Application as fuels requires hydrogenation of the double bonds in the respective molecules to ensure clean combustion. This hydrogenation can be performed either directly with elemental hydrogen or indirectly via transfer hydrogenation with a Liquid Organic Hydrogen Carrier. In this study, the thermochemical fundamentals of these reaction has been evaluated. For this task, for a first time a combination of experimental thermochemistry and quantum-chemical molecular modelling has been applied. The results show the hydrogenation of the respective structures is thermodynamically highly favourable. Correspondingly, dehydrogenation would be comparatively unfavorable. Yet, for a fuel no dehydrogenation is required. As an alternative to conventional hydrogenation, transfer hydrogenation, which is often subject to partial conversions due to limitations by the reaction equilibrium, can be realized with a high degree of conversion. While the entropy of reaction for hydrogen transfer from cyclohexyl-structures to terpene structures is close to zero, the enthalpy of reaction is highly negative. This leads to a Gibbs energy of reaction which is clearly negative and ensures a large thermodynamic driving force for the reaction. As a consequence, downstream processing, which is usually very demanding for transfer hydrogenations, is comparatively easy. These finding underline the great potential of these bio-derived substances for conversion into sustainable fuels.

Water transport across the membrane of a direct toluene electro-hydrogenation electrolyzer: Experiments and modelling

Toluene/methylcyclohexane is a promising liquid organic hydride for hydrogen storage and transport under ambient conditions. Direct toluene electro-hydrogenation electrolyzers, utilizing proton exchange membrane technology, offer benefits in reducing the reversible decomposition voltage and eliminating theoretical heat losses associated with conventional hydrogenation methods. Nevertheless, water transport across the membrane can inhibit the supply of toluene to reaction sites at the cathode. This study investigates water transport across the Nafion™ 117 membrane of an in-house electrolyzer cell, employing sulfuric acid and toluene solutions as the anode and cathode reactant, respectively, and operating at current densities from 0.1 to 0.8 A/cm2. The experiments show that the cathode toluene concentration has a negligible effect on drag water, while water flux increases with electric current and decreases with higher anode sulfuric acid concentrations. The modelling approach assumes electro-osmosis and diffusion mechanisms govern water transport. Simulations predict a linear decrease in the electro-osmotic drag coefficient from 2.3 to 1.6 as the sulfuric acid concentration rises from 0.1 to 1.5 mol/L, while the back diffusion flux increases linearly up to 2 mg/(min·cm2). These findings closely align with experimental data and previous literature, despite the high complexity of water transport in polymer electrolyte membranes.

Water-assisted hydrogenation of aromatics under ambient conditions over Ru catalyst: A combined experimental and computational investigation

Conventional hydrogenation of lignin-derived compounds requires high H2 pressures and temperatures, and yet, achieving the desired conversion and selectivity remains a challenge. Herein, a novel reaction system with a ruthenium catalyst and water as a solvent is developed for the selective hydrogenation of lignin-derived aromatics to corresponding ring-saturated products under ambient conditions (room temperature, and 1 bar H2 pressure). Using a synergistic combination of catalytic experiments, advanced characterization techniques and quantum mechanical simulations, we elucidate that Ru catalyst switches its selectivity from deoxygenation in gas phase to ring hydrogenation in the condensed phase. Water partially dissociates and adsorbs on the catalyst surface as a combination of hydroxyl fragments, H atoms, and physisorbed molecules, and this is critical for Ru to flip its selectivity in the aqueous phase. Experimental results demonstrate a high conversion (>99 %) and >75 % selectivity towards the total hydrogenated products in the presence of water, corroborating the computational results in which kinetic free energy barriers for direct hydrogenation steps reduced to 70 kJ/mol and barrier for direct dehydroxylation increased from 63 kJ/mol to 202 kJ/mol in the case of phenol. Furthermore, H from dissociated water molecules is utilized in the hydrogenation and water also gets regenerated utilizing external hydrogen supply, thus acting as a shuttler for the external hydrogen.

Effect of Electrolyte Composition and Mass Transport on Electrochemical Hydrogenations of a Terminal Alkynol

AbstractElectrochemical hydrogenations (EChH) constitute a sustainable alternative to conventional thermocatalytic hydrogenation. Here, we explored the EChH of the vitamin E and A synthon 2‐methyl‐3‐butyn‐2‐ol in a scalable zero‐gap electrolyzer and revealed crucial effects of electrolyte composition and convection parameters to consider for optimization. We show that high Faraday efficiencies can be achieved with low to moderate concentrations of neutral or alkaline electrolytes. While the flow rate has a strong impact on performance, electrode compression and cell orientation can be used for fine tuning. We achieved a Faraday efficiency of up to 69 % for the targeted semi‐hydrogenated product at current densities of 80 mA cm−2 at 2.2 V cell voltage and a concentration of 1 M 2‐methyl‐3‐butyn‐2‐ol.

Metal-facilitated, sustainable nitroarene hydrogenation under ambient conditions

Hydrogenation is a critical reaction in the chemical industry, yielding a range of important compounds such as fine chemicals, pharmachemicals and agrochemicals. However, conventional hydrogenation typically requires pressurized hydrogen, high temperatures and involves noble metal catalysts. We proposed a two-step hydrogenation process, utilizing water as the hydrogen source for the industrially important reduction of nitroarenes to anilines. A metal or reduced metal oxide, which can be obtained from solar thermal or electrochemical reduction, acts as the active site for nitrobenzene adsorption, H2O dissociation and in-situ hydrogen generation. Among the 15 metal and reduced metal oxides investigated, Zn and Sn emerged as highly efficient catalysts for the reduction of a broad range of organic nitro compounds under mild conditions, with H2 utilization efficiency 1–2 orders of magnitude above the state-of-the-art. The presented protocol provides extra dimensions for designing and optimizing conventional hydrogenation process with an alternative pathway. The reactive hydrogen atoms generated in-situ effectively overcome the barriers associated with hydrogen gas dissolution and its subsequent dissociation on the catalyst surface, thereby greatly enhancing the overall effectiveness for the hydrogenation reaction. This research potentially establishes a sustainable, generally applicable alternative to conventional hydrogenation methods, simultaneously presenting a viable solution for renewable energy storage.

Valorization of hemicellulosic sugars to sugar alcohols by Raney nickel mediated hydrogen transfer

The versatility of the pathway to produce polyols from sugars through catalytic transfer hydrogenation (CTH) using commercial Raney nickel catalysts and 1,4-butanediol as hydrogen source has been explored. The results reveal that the nickel purity of the catalyst is a key parameter in process selectivity and presents the CTH route as a promising alternative to conventional hydrogenation processes, effective for the complete valorization of the sugar platform, including hexoses, pentoses and disaccharides. The study uncovers a significant influence of sugar structure on the resulting reactions, with threo-configured sugars displaying enhanced selectivity, while erythro-configured sugars demonstrate elevated conversion rates and the production of a broader spectrum of sugar alcohol isomers. Furthermore, a computational study, using density functional theory (DFT) calculations, has been carried out to describe the performance of the disaccharides and correlate it with their activity in the reaction media.

Evaluation of industrial aromatic oils as potential hydrogen carriers: Study of the hydrogenation step

Industrial organic streams (oils) with high concentration of aromatics compounds are present in different carbochemical and petrochemical processes. These aromatic compounds are potential hydrogen carriers through hydrogenation-dehydrogenation cycles. For this purpose, catalytic hydrogenation of three different aromatic oils using conventional hydrogenation catalysts is considered in this work. Two oil samples (petrochemical Oil A and carbochemical Oil B) enriched with polyaromatic compounds, along with a manufactured oil of petrochemical origin (SolvessoTM 200), were hydrogenated using Pt/γ-Al2O3 and Pd/γ-Al2O3 catalysts. The study aims to work under mild conditions to avoid secondary reactions and cracking, which is important for using these oils as potential LOHCs. The methodology involved using a stainless-steel autoclave reactor and analysing the composition of the oils and reaction products using gas chromatography and mass spectrometry. Diaromatic compounds were found to be the most reactive, reactant conversion depending on the catalyst and reaction temperature. However, the presence of tri and tetra-aromatic compounds hinder the reaction. Moreover, nitrogenated aromatic compounds are extremely reactive at these conditions. Comparison of SolvessoTM 200 with benzyltoluene, an established LOHC, resulted in promising results. Thus, both Oil A and B, after a purification step, would have interesting qualities to be used as LOHCs with the added advantage of its low price.

Modelling of the Water Mass Transport through the Membrane of Direct Toluene Electro-Hydrogenation Electrolyzers

The organic hydride toluene/methylcyclohexane (MCH) is an attractive carrier for the bulk and long-distance transport of green hydrogen. On the other hand, the direct toluene electro-hydrogenation in a proton exchange membrane electrolyzer exhibits advantages concerning the conventional two-step toluene hydrogenation process, such as the lower theoretical voltage by avoiding thermal losses [1]. Figure 1 (a) shows the internal structure and illustrates the basic working principle of this electrochemical device.However, the effective toluene supply to the cathode catalyst is a central issue. It is assumed that the accumulation of water dragged from the anode side inhibits the toluene mass transport to the reaction site [2]. Therefore, in practice, a fraction of the toluene stream entering the cathode fails to convert to MCH; instead, hydrogen bubbles are generated. According to the theoretical approach illustrated in Fig. 1 (a), protons transported across the membrane and can be the carrier of associated water. Nevertheless, the water transfer mechanism inside a cell is complex, diverse, and unclear (e.g., as mist, small droplet) [3].According to most conventional modelling approaches, electro-osmosis and back diffusion mainly govern the total water flux through electrolytic membranes. The open literature dealing with PEM fuel cells agrees that the water content of the membrane (correlated with the water activity by earlier studies) is a central factor concerning not only these mass transport mechanisms inside the membrane, but also concerning the mass transfer resistance on its surface. Indeed, to calculate both the electro-osmotic drag and the diffusion coefficients, authors have developed numerous correlations based on a relationship with the membrane water content. However, the experimental data available in the open literature dealing with PEM fuel cells devices largely disagree. Complex factors such as the Schroeder’s Paradox in Nafion® membranes [4] can explain those discrepancies. This leads into a huge uncertainty in the parametrization of those parameters involved in the numerical modelling and simulation of the water transport in electrochemical devices based on PEM technology [5].The objective of this work is to qualitatively study, through numerical simulation, the influence of the main parameters involved in the transport of water through the electrolytic membrane of a direct toluene electro-hydrogenation electrolyzer. To accomplish this aim, a sensitivity analysis was conducted, and the probability distributions set for each modelling parameter (i.e., potential variation range) are consistent with the state-of-the-art. The anode reactants considered were pure water and also diluted solutions of sulfuric acid with concentrations between 0.1-1.5 L/mol. Figure 1 (b) shows the preliminary results obtained when supplying pure water as anode reactant and under the assumption of null water mass transport by back diffusion mechanism. The experimental data gathered from the monitoring of an in-house toluene electro-hydrogenation cell are used as reference to discuss the results obtained from the simulations and to tighten the modelling parameters. Acknowledgements Antonio Atienza-Márquez acknowledges the Ministerio de Universidades of Spain and the Recovery, Transformation and Resilience Plan for financially supporting the postdoctoral contract 2021URV-MS-01.

Exploring Hydrogen Sources in Catalytic Transfer Hydrogenation: A Review of Unsaturated Compound Reduction.

Catalytic transfer hydrogenation has emerged as a pivotal chemical process with transformative potential in various industries. This review highlights the significance of catalytic transfer hydrogenation, a reaction that facilitates the transfer of hydrogen from one molecule to another, using a distinct molecule as the hydrogen source in the presence of a catalyst. Unlike conventional direct hydrogenation, catalytic transfer hydrogenation offers numerous advantages, such as enhanced safety, cost-effective hydrogen donors, byproduct recyclability, catalyst accessibility, and the potential for catalytic asymmetric transfer hydrogenation, particularly with chiral ligands. Moreover, the diverse range of hydrogen donor molecules utilized in this reaction have been explored, shedding light on their unique properties and their impact on catalytic systems and the mechanism elucidation of some reactions. Alcohols such as methanol and isopropanol are prominent hydrogen donors, demonstrating remarkable efficacy in various reductions. Formic acid offers irreversible hydrogenation, preventing the occurrence of reverse reactions, and is extensively utilized in chiral compound synthesis. Unconventional donors such as 1,4-cyclohexadiene and glycerol have shown a good efficiency in reducing unsaturated compounds, with glycerol additionally serving as a green solvent in some transformations. The compatibility of these donors with various catalysts, substrates, and reaction conditions were all discussed. Furthermore, this paper outlines future trends which include the utilization of biomass-derived hydrogen donors, the exploration of hydrogen storage materials such as metal-organic frameworks (MOFs), catalyst development for enhanced activity and recyclability, and the utilization of eco-friendly solvents such as glycerol and ionic liquids. Innovative heating methods, diverse base materials, and continued research into catalyst-hydrogen donor interactions are aimed to shape the future of catalytic transfer hydrogenation, enhancing its selectivity and efficiency across various industries and applications.

Pt/CeCrO2−x: A multifunctional catalyst for tandem catalysis of lignocellulose hydro-liquefaction and Guerbet reaction

Catalytic transfer hydrogenation (CTH) of lignocellulose liquefaction using renewable ethanol presents a promising alternative to conventional hydrogenation techniques. However, the development of efficient and stable multifunctional catalysts remains a significant challenge. Herein, a Pt/Ce9Cr1O2−x catalyst was developed to facilitate the CTH reactions and achieve nearly complete utilization of lignocellulose. Isotope labeling experiments were conducted to elucidate the mechanism of CTH. The introduction of Cr3+ increased the density of surface oxygen vacancies, consequently enhancing the hydrodeoxygenation ability and metal anchoring. The solid solution structure promotes the electrons transfer from Cr atoms to Pt atoms, forming electron-rich Ptδ+ species that promote ethanol dehydrogenation and lignocellulose hydrodeoxygenation. Furthermore, Pt/Ce9Cr1O2−x catalyst provided optimal acid-base sites and hydroxyl groups, thereby improving ethanol upgrading efficiency and wettability.

An investigation of the Ni/carbonate interfaces on dual function materials in integrated CO2 capture and utilisation cycles

CO2 capture and utilisation (CCU) is a promising strategy to effectively mitigate the adverse greenhouse effects caused by CO2 emissions at an industrial scale. Through a process intensification strategy known as integrated CO2 capture and utilisation (ICCU), CO2 capture and catalytic CO2 conversion can be achieved in a single process with the use of dual function materials (DFMs), which are both CO2 sorbents and CO2 conversion catalysts. Given the significantly different operating conditions of ICCU from conventional catalytic CO2 hydrogenation, the catalytic mechanism of DFMs, especially during CO2 hydrogenation, needs to be thoroughly investigated. In this study, the relationship between the nature of the Ni/carbonate interfaces and the performance of Ni-based DFMs over ICCU cycles is systematically investigated. A series of Ni/alkaline earth carbonate DFMs were synthesised with varying Ca:Mg ratios to simulate different metal-carbonate model interfaces. At 400 °C, CH4 formation with nearly 100% CH4 selectivity was achieved on Ni/CaCO3 over 15 ICCU cycles. In general, Ni/CaCO3 interfaces correspond to higher CO2 conversion and higher CH4 selectivity than Ni/MgCO3 interfaces. Such trend may be attributed to the higher surface basicity of CaO and the higher thermal stability of CaCO3. As a consequence, the hydrogenation of the Ni/CaCO3 interface proceed via the formate pathway, in which carbonates are consecutively converted to surface formates, methoxyl, methyl species and eventually desorb as methane. This reaction model is applicable to the hydrogenation of both surface carbonate and bulk carbonates, although the former proceeds with much faster kinetics. On the weakly alkaline Ni/MgCO3 interface, MgCO3 preferentially decomposes to form gaseous CO2, which is subsequently hydrogenated via the reverse-water-gas-shift pathway, with CO as the key reaction intermediate. Interestingly, in situ infrared spectroscopy shows similar surface significant species during the direct hydrogenation of DFMs and during the conventional catalytic hydrogenation of molecular CO2, suggesting that the catalytic mechanisms during the two operating regimes are highly correlated.

Photocatalytic Transfer Hydrogenation Reactions Using Water as the Proton Source

Transfer hydrogenation using liquid hydrogen carriers as the direct proton sources under mild conditions has received extensive attention in the research area of organic synthesis. The emerging photocatalytic water-donating transfer hydrogenation (PWDTH) is a promising alternative over the conventional hydrogenation technology due to the advantages of being eco-friendly. This paper focuses on the recent advances in the rising and rapidly developing field of PWDTH reactions, devoted to elucidating the mechanism of the hydrogen transfer process and rationalizing the design principles of efficient photocatalysts. Finally, the current challenges and future opportunities are described.

Advances and prospects in electrocatalytic hydrogenation of aromatic hydrocarbons for synthesis of “loaded” liquid organic hydrogen carriers

Liquid organic hydrogen carriers (LOHC) are considered as the safest and most promising candidates for hydrogen storage, meeting the requirements of sufficient weight and volume capacity (over 6 wt%), hydrogenation-dehydrogenation reversibility and low cost. The prospects of catalytic hydrogenation of polycyclic hydrocarbons for the production of LOHC are considered. The comparison shows that electrocatalytic hydrogenation of aromatic LOHC is highly advantageous, since this approach eliminates the use of gaseous hydrogen in the production of "loaded" LOHC and therefore is safer than the conventional hydrogenation. The advantage of electrocatalytic hydrogenation compared to catalytic hydrogenation is that high temperatures are not required. The approaches to increase the efficiency of electrocatalytic hydrogenation are discussed.

Cobalt-Doped g-C3N4 Nanosheets for One-Pot Synthesis of Imines under Mild Conditions

The traditional synthesis methods of imines are limited by expensive catalysts, harsh reaction conditions, and low atomic efficiency. The one-pot synthesis of imines using nitrobenzene and benzaldehyde is a promising reaction path. Transition metal catalytic transfer hydrogenation offers advantages in terms of safety. It has attracted the attention of industrial production and academia as an alternative to conventional hydrogenation processes. Herein, we report an environmentally friendly Co/g–C3N4 nanocatalyst that uses inexpensive cobalt as the fundamental source of feedstock; formic acid is applied as the hydrogen donor, and the yield of the synthesis method can reach 96% under mild conditions. Besides, the catalyst proved to be stable and efficient despite five successive cycles of testing. Moreover, the excellent catalytic activity was demonstrated to be derived from the Co–Nx site based on the mechanistic analysis and characterization. For this work, a pathway will be developed to produce transfer hydrogenation of nitro compounds.

Hydrogen Production and Utilization in a Membrane Reactor.

Industrial hydrogenation consumes ~11 Mt of fossil-derived H2 gas yearly. Our group invented a membrane reactor to bypass the need to use H2 gas for hydrogenation chemistry. The membrane reactor sources hydrogen from water and drives reactions using renewable electricity. In this reactor, a thin piece of Pd separates an electrochemical hydrogen production compartment from a chemical hydrogenation compartment. The Pd in the membrane reactor acts as (i) a hydrogen-selective membrane, (ii) a cathode, and (iii) a catalyst for hydrogenation. Herein, we report the use of atmospheric mass spectrometry (atm-MS) and gas chromatography mass spectrometry (GC-MS) to demonstrate that an applied electrochemical bias across a Pd membrane enables efficient hydrogenation without direct H2 input in a membrane reactor. With atm-MS, we measured a hydrogen permeation of 73%, which enabled the hydrogenation of propiophenone to propylbenzene with 100% selectivity, as measured by GC-MS. In contrast to conventional electrochemical hydrogenation, which is limited to low concentrations of starting material dissolved in a protic electrolyte, the physical separation of hydrogen production from utilization in the membrane reactor enables hydrogenation in any solvent or at any concentration. The use of high concentrations and a wide range of solvents is particularly important for reactor scalability and future commercialization.

Life cycle net energy assessment of sustainable H2 production and hydrogenation of chemicals in a coupled photoelectrochemical device

Green hydrogen has been identified as a critical enabler in the global transition to sustainable energy and decarbonized society, but it is still not economically competitive compared to fossil-fuel-based hydrogen. To overcome this limitation, we propose to couple photoelectrochemical (PEC) water splitting with the hydrogenation of chemicals. Here, we evaluate the potential of co-producing hydrogen and methyl succinic acid (MSA) by coupling the hydrogenation of itaconic acid (IA) inside a PEC water splitting device. A negative net energy balance is predicted to be achieved when the device generates only hydrogen, but energy breakeven can already be achieved when a small ratio (~2%) of the generated hydrogen is used in situ for IA-to-MSA conversion. Moreover, the simulated coupled device produces MSA with much lower cumulative energy demand than conventional hydrogenation. Overall, the coupled hydrogenation concept offers an attractive approach to increase the viability of PEC water splitting while at the same time decarbonizing valuable chemical production.

Photocatalytic conversion of carbon dioxide on triethanolamine: Unheeded catalytic performance of sacrificial agent

Potential catalytic performance of sacrificial agents triethanolamine (TEOA) has not been explored yet, seriously affecting the evaluation of catalyst performance and reaction mechanism. Herein, we report direct evidence of TEOA, a popular sacrificial agent in CO2 photoreduction, photocatalytic conversion of CO2 into CO and CH4 for the first time. Combining experimental and theoretical studies, it is corroborated that TEOA with terminal hydroxyl group as active site serves as a photocatalyst possessing appropriate energy level for the ultraviolet light response. Comprehensive investigations endorsed that the two products of CH4 and CO are derived from conventional photocatalytic CO2 hydrogenation and photoinduced homocleavage of RO-COOH followed by a hydrogen atom transfer process, respectively. The current work demonstrates the nonnegligible catalytic influence of TEOA and provides guidance in choosing suitable sacrificial agents during solid–liquid photocatalytic redox reactions.

Selective Furfuryl Alcohol Production from Furfural via Bio-Electrocatalysis

The catalytic reduction of renewable furfural into furfuryl alcohol for various applications is in the ascendant. Nonetheless, the conventional chemo-catalysis hydrogenation of furfural always suffers from poor selectivity, harsh conditions, and expensive catalysts. Herein, to overcome the serious technical barriers of conventional furfuryl alcohol production, an alternative bio-electrocatalytic hydrogenation system was established under mild and neutral conditions, where the dissolved cofactor (NADH) and the alcohol dehydrogenase (ADH) participated in a tandem reaction driven by the electron from a novel Rh (III) complex fixed cathode. Under the optimized conditions, 81.5% of furfural alcohol selectivity can be realized at −0.43 V vs. RHE. This contribution presents a ‘green’ and promising route for the valorization of furfural and other biomass compounds.

Promoting electrocatalytic hydrogenation of 5-hydroxymethylfurfural using buffer electrolytes as proton-donating motifs: Theoretical predictions and experimental validations

Electrocatalytic hydrogenation (ECH) represents a promising alternative to conventional hydrogenation techniques with high-pressure H2 as a reductant. The proton-donating motif is an important factor governing the reaction efficiency but is usually overlooked in the ECH process. Herein, on the basis of density functional theory (DFT) predictions and experimental validations, we demonstrate that proton-buffer salts such as phosphate, carbonate and borate can greatly promote ECH efficiency. The DFT results predict that the buffer species can outperform water in donating protons for *CO hydrogenation into *C-OH via the Langmuir-Hinshelwood or proton-coupled electron transfer (PCET) mechanism, thus promoting the hydrogenation of carbonyl compounds. The experimental results demonstrate that with the buffer-promoting effects, 5-hydroxymethylfurfural (HMF) can be effectively converted at an efficiency of 96 % into the value-added 2,5-dihydroxymethylfuran (DHMF) with a yield of 80 % over cobalt oxide (Co3O4) nanoarray catalysts under near-neutral buffer electrolyte. In situ Raman analysis and kinetic isotope experimental results reveal that the real mechanism is a combined Langmuir-Hinshelwood and PCET process. Such a buffer-promoting strategy also exhibits wide applicability in ECH of various other carbonyl compounds with different electrode catalysts. This work may provide a deep understanding of the ECH process and open up new opportunities to design effective systems for the conversion of HMF into value-added products.

Advanced High-Loaded Ni–Cu Catalysts in Transfer Hydrogenation of Anisole: Unexpected Effect of Cu Addition

Binary Ni–Cu heterogeneous catalysts are known to demonstrate excellent activity in conventional hydrogenation of phenolic compounds, and Cu addition facilitates hydrodeoxygenation (HDO). In this study, we aimed to show the effect of Cu on the specific catalytic activity and selectivity of Ni–Cu catalysts in transfer hydrogenation, in which 2-PrOH was used as a solvent and an H donor. Catalytic transformations of anisole were studied in sub- and supercritical alcohol at 150 and 250 °C. The catalysts were prepared using an environmentally friendly supercritical antisolvent coprecipitation method, which makes it possible to obtain well-dispersed particles (less than 7 nm) at high metal loading (up to 50 wt.%). When copper is added, deactivation of the catalyst in transformations of anisole, including HDO, is observed. The experimental data and the appropriate kinetic analysis demonstrate that there is a decrease in the rate of anisole conversion accompanied by an increase in the concentration of acetone formed during the dehydrogenation of 2-PrOH.