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Lignin obtained by hydrogenolysis of lignocellulose biomass is a prospective source of valuable green fuels and chemicals such as monophenols. One of the key factors in the chemical decomposition of lignin to monophenols is an efficient catalyst. Inert porous materials such as hypercrosslinked polymers are suitable catalytic supports for the immobilization of noble and transition metal nanoparticles. However, such polymers do not have acidic properties, which are crucial for catalyzing hydrolysis. In this work, we report novel, efficient catalysts for lignin hydrogenolysis to produce valuable monophenolic compounds. The synthesized catalysts contained Ni, Ru, and Ni–Ru nanoparticles supported on SiO2-coated hypercrosslinked polystyrene (SiO2@HPS). Ni-Ru/SiO2@HPS demonstrated remarkable stability without any loss of the metallic phase and a high yield of monophenols (>42 wt.%) at close to full lignin conversion (>95 wt.%). This result was attributed to the synergy between the two metals and the support’s surface acidity. All catalysts were fully characterized by a series of physico-chemical methods.

In this work, novel bifunctional catalysts based on the polymeric network of hypercrosslinked polystyrene were developed for the process of anthracene hydrocracking in the medium of supercritical propanol-2. The synthesized catalysts contain NiOOH as an active phase and the SiO2 as Bronsted acid sites supported on the highly porous support. The influence of the synthesis method and silica precursor type on the textural properties and the active phase composition was studied. The catalyst obtained by the hydrothermal method using tetraethoxysilane as a silica precursor seems to be the most optimal providing both high surface area, bimodal pore size distribution, and high acidity, and, thus, higher catalytic activity in anthracene hydrocracking.

Hydrotreatment of bio-oil oxygen compounds allows the final product to be effectively used as a liquid transportation fuel from biomass. Deoxygenation is considered to be one of the most promising ways for bio-oil upgrading. In the current work, we describe a novel approach for the deoxygenation of bio-oil model compounds (anisole, guaiacol) using supercritical fluids as both the solvent and hydrogen-donors. We estimated the possibility of the use of complex solvent consisting of non-polar n-hexane with low critical points (Tc = 234.5 ºC, Pc = 3.02 MPa) and propanol-2 used as H-donor. The experiments were performed without catalysts and in the presence of noble and transition metals hydrothermally deposited on the polymeric matrix of hypercrosslinked polystyrene (HPS). The experiments showed that the presence of 20 vol. % of propanol-2 in n-hexane results in the highest (up to 99%) conversion of model compounds. When the process was carried out without a catalyst, phenols were found to be a major product yielding up to 95 %. The use of Pd- and Co-containing catalyst yielded 90 % of aromatic compounds (benzene and toluene) while in the presence of Ru and Ni cyclohexane and methylcyclohexane (up to 98 %) were the main products.

The structure and activity of novel combined ruthenium-containing catalysts based on hypercrosslinked polystyrene modified with Fe3O4 and SiO2 were studied. The modification of the polymeric support surface aimed at imparting new properties to the catalysts is a prospective approach for the development of highly efficient catalytic systems involved in various processes. The synthesized samples are characterized by a high specific surface area and a high catalytic activity in the liquid-phase Fischer—Tropsch synthesis providing a yield of liquid hydrocarbons C6-C12 up to 82%.

Carbon materials are widely used in catalysis as effective catalyst supports. Carbon supports can be produced from coal, organic precursors, biomass, and polymer wastes. Biomass is one of the promising sources used to produce carbon-based materials with a high surface area and a hierarchical structure. In this review, we briefly discuss the methods of biomass-derived carbon supported catalyst preparation and their application in biodiesel production, organic synthesis reactions, and electrocatalysis.

Nickel- and cobalt-containing particles immobilized on a polymer support (hypercrosslinked polystyrene) by the hydrothermal method are studied. The composition, structure, and morphology of the synthesized metal–polymer composites are analyzed. It is shown that hydrothermal synthesis provides the formation of metal–polymer composites with a uniformly distributed metal-containing phase without significant changes in the composition and structure of the polymer support. It is found that, under conditions of superheated water, the pore structure of the support undergoes rearrangement to form pores with a diameter of 20–100 nm; this is one of the key factors for many catalytic processes involving large molecules.

A physicochemical study of cobalt-containing (10 wt %) silica-supported Fischer–Tropsch catalysts was carried out. The catalysts were obtained under subcritical conditions (T = 200°C, P = 8 MPa) using water (Tc = 374.1°C, Pc = 22.1 MPa) and propanol-2 (Tc = 235.6°C, Pc = 5.8 MPa). The obtained samples were compared with a 10 wt % Co/SiO2 catalyst prepared by incipient-wetness impregnation. Comparison of the properties of catalysts in the liquid-phase Fischer–Tropsch synthesis showed that the sample prepared in subcritical water was the most active and selective to aliphatic C6–C7 hydrocarbons. This sample is characterized by a high surface area (131.7 m2/g), a uniform distribution of particles in the active phase with an average size of 5 nm and higher accessibility of cobalt species for reagents. According to XPS data, the composition of catalyst active phase is mainly represented by two compounds: Co(OH)2 and Co3O4.

In the current work, the use of Ni-containing catalyst on the base of hypercrosslinked polystyrene in the stearic acid (SA) hydrodeoxygenation (HDO) in the medium of supercritical n-hexane is presented. The catalyst was synthesized by the hydrothermal deposition of Ni-containing particles into the pores of the polymeric matrix in the medium of superheated water. It was found that the catalyst is characterized by the high surface area and the uniform deposition of the active phase on the catalyst surface. Ni in the catalyst is represented by NiOOH. The mean particle diameter of the active phase was found to be 5.5 nm. The catalyst showed high efficiency in the SA HDO in the medium of supercritical n-hexane reaching the C16–C17 yield up to 90 at 100% substrate conversion. It was shown that the catalyst maintained its activity in minimum five consecutive runs without sufficient loose selectivity.