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Halogenated porous melamine polymers were demonstrated as an efficient catalyst for CO2-epoxide cycloaddition, selectively (>99%) producing C3-C12 cyclic carbonates in excellent yields (upto 99%) under solvent and co-catalyst free conditions. The halogenated polymers outperformed benchmark catalysts incorporating only basic (N-doped carbon, ZIF-8, N-rich melamine polymer) or nucleophilic (TBAB, KI) sites. The superior catalytic performance of these inexpensive polymers was attributed to their unique surface chemistry incorporating abundant, stable basic N sites (amine N and protonated N) and nucleophilic (Cl-, Br- or I-) that enabled simultaneous activation of both epoxide and CO₂ molecule (supported by kinetic and DFT studies). Further, among halogenated polymers a Br- containing material (PMF_Br) presented highest activity owing to its balanced CO₂-philicity and strong nucleophilicity. Most importantly, PMF_Br was robust, reusable and maintained stable performance for continuous production of C3-C4 cyclic carbonate (120 ^oC, 0.3-0.83 h^-1 WHSV_epoxide and 15 bar) in a fixed-bed reactor during 60-190 h TOS.

The present invention provides a method for producing hydrocarbons having 6 to 20 carbon atoms, comprising the steps of: a) providing a feedstock comprising saturated fatty acids, and/or derivatives thereof; b) deoxygenating the feedstock in the presence of a metal free hydrogenation and decarboxylation catalyst under low-pressure hydrothermal conditions, wherein the temperature is in the range 350-400 °C and the pressure is in the range 10-30 bar; and wherein the catalyst is a heteroatom-doped carbon material. Furthermore, there is provided a system for preforming the method in a single reactor (R) system comprises a bed of a carbon catalyst facilitating simultaneous hydrogenation and decarboxylation

For the first time, a tandem catalytic material, 5 wt. % Pd/NbOPO₄, was utilized in the depolymerization of wood in supercritical ethanol under hydrogen atmosphere. The experiments were conducted under various conditions, with fresh, and acetone extracted birch. A comprehensive analysis was performed to elucidate the dissolution efficiency and achieved product distribution. The results indicated that with fresh birch, 34 wt. % of lignin monomer yield with 84 wt. % delignification efficiency were obtained while with extracted wood, 35 wt. % of lignin monomer yield with 78 wt. % delignification efficiency were achieved. The total lignin monomer content extracted from the fresh birch is composed of 76.9 wt. % of dimethoxyphenols and 16.5 wt. % with the guaiacol structure. Major lignin monomer product was homosyringaldehyde (61.9 wt. %). With extracted wood, 93.2 wt. % of dimethoxyphenols (63.6 wt. % homosyringaldehyde) and 6.8 wt. % of guaiacol-monomers were achieved. It was concluded that the depolymerization occurred via breaking of the ether bonds in lignin, including ether hydrolysis by Lewis acid sites over the solid acid catalyst and with subsequent deoxygenation of monophenols over Pd. In addition, an extraction process was proposed to extract the aromatic fraction from the obtained biocrude.

A Ru-loaded carbon material with characteristic surface chemistry (Br∅nsted acidic phosphate groups, Lewis basic N-groups selected from the group consisting of Lewis basic pyridinic, pyrrolic and quaternary N-groups and oxygen functional groups) is shown to exhibit excellent activity, selectivity and stability upon hydrogenation of aqueous levulinic acid (0.47M and 0.95M) to γ-alerolactone with near stochiometric H₂ under mild conditions (80-95°C). The material demostrated remarkable stability in a fixed-bed reactor under continuous flow conditions, maintaining high activity, and γ-valerolactone selectivity during  ∼ 1250h time on stream operating at 3-5 bar, 80-95 °C and low H₂/levulinic acid ratio (4-17). The exceptional catalytic performance and stability of the multifunctional Ru-catalyst was attributed to the unique surface chemistry of carbon support that stabilized the Ru nanoparticles on the surface nitrogen and oxygen defects, and promoted 4-hydroxypentanoic acid cyclization over acidic phosphate and RuOx/RuO₂ sites.

One-pot depolymerisation of lignin, extracted from Miscanthus plants under acidic (formic acid lignin, FAL) or basic (ammonia lignin, AL) conditions, over Ni- and/or Nb-doped SBA-15, was the subject of this study. The aforementioned acid catalysts prepared by sol–gel method were characterized by SEM–EDX, ATR-FTIR, Raman, XRD, N2 adsorption/desorption isotherms, CO2-TPD and NH3-TPD techniques. The increase in acidity due to the insertion of Nb into the SBA-15 structure promoted the selective cleavage of β–O–4 from ammonia lignin, leading to aromatic monomer yields up to 22 wt% in 6 h at 180 °C under 50 atm H2. The catalytic performances of Ni-Nb-SBA-15 as well as its stability were influenced by the chemical composition of the lignin sample as results of its extraction from the Miscanthus plant.

In this study, nanostructure kazakhstanite-like iron vanadate (FexV3xOy.H2O) was synthesized and calcined at different temperatures (100-800 °C) in a nitrogen atmosphere. The material was used to modify screen-printed carbon electrodes to achieve an electrocatalytic effect on the surface. The relationship between calcination conditions and the catalytic performance of the electrode towards the oxidation of chemotherapeutic drugs, including methotrexate (MTX) and folinic acid (FA), was studied. Various spectroscopic, microscopic, and electrochemical methods were used to characterize the synthesized materials. The results show that calcination induces changes in the electronic structure, nanostructure morphology, electroactive surface area, and electrocatalytic performance of the material. Screen-printed carbon electrode modified with FexV3xOy calcinated at 450 °C (SPC/FexV3xOy-450) was used to develop a voltammetric sensor for the determination of MTX and FA in blood serum. The response of the SPC/FexV3xOy-450 towards the electrooxidation of MTX and FA was the highest in comparison to the bare SPC and SPC/FexV3xOy calcined at other temperatures. The SPC/FexV3xOy-450 exhibited a linear relationship over a wide concentration range: 0.005-200 µM for MTX and 0.05-200 µM for FA. The detection limit was 2.85 nM for MTX and 7.79 nM for FA. Compared to conventional methods, the SPC/FexV3xOy-450 sensor had a short response time (5 min) for simultaneous detection of MTX and FA without signal interferences from coexisting electroactive compounds. The accurate and precise determination of MTX in the presence of FA confirmed the potential clinical applications of SPC/FexV3xOy-450 for therapeutic drug monitoring during chemotherapy.

Herein, we demonstrate that surface acid-base properties have marked effect upon the performance (activity, selectivity and stability) of supported Ru catalysts upon tandem hydrocyclization (hydrogenation-dehydration) of aqueous levulinic acid. A mesoporous bi-functional Ru/NbOPO4/SBA-15 catalyst incorporating highly dispersed Ru sites and well balanced strong Brønsted acidic sites (optimum B/L and M+S/W ratio) was identified, which outperformed the benchmark monofuncational (Ru/SBA-15, Ru/MCM-41) and physically blended bi-functional catalysts (Ru catalysts mixed with acid co-catalysts e.g. NbOPO4/Amberlyst-15). Further, the catalyst also demonstrated remarkable stability in a fixed-bed reactor, maintaining steady activity and γ-valerolactone selectivity (72-86%) during ca. 300 h time on stream (10 bar, 90-100 oC), corroborating its industrial potential. The exceptional performance and durability of the bi-functional catalyst was attributed to the presence of well dispersed hydrothermally and chemically stable acid (NbOPO4) and redox (Ru) sites.

In this work, a low-cost, light-weight, highly efficient, and durable electrode in which NiFe-layered double hydroxide is electrodeposited on a carbon nanofiber (CNF) core supported on a carbon foam (CF) is introduced. The resulting 3D NiFe-CNFs-CF electrode shows excellent oxygen evolution reaction and hydrogen evolution reaction performance in alkaline media. When used as an anode and a cathode in the same cell, a current density of 10 mA cm−2 is achieved, at a cell voltage of 1.65 V. Moreover, good stability over a long testing time (50 h) is demonstrated. The ternary hybrid electrode gives rise to an excellent performance-to-weight ratio owing to its very low bulk density (≈34 mg cm−3) inherited from super lightweight components composed of CF and CNFs. The developed electrode can potentially be used in large-scale alkaline water electrolysis, in facilities such as offshore hydrogen production platforms, which can complement the variable renewable energy production of wind farms through hydrogen storage and fuel cells.

Hydrothermal deoxygenation of tall oil fatty acids (TOFA) was investigated in the presence of aqueous formic acid (0.5–7.5 wt%) as a H₂ donor in the presence of subcritical H₂O pressure (569–599 K). Pd and Ru nanoparticles supported on carbon (5% Pd/CSigma, 5% Ru/CSigma, 10% Pd/CO850_DP, and 5% Ru/COPcomm_DP) were found to be efficient catalysts for deoxygenation of TOFA. The reaction pathway was mainly influenced by the concentration of formic acid and the catalyst. In case of Pd catalysts, in the presence of 0–2.5 wt% formic acid, decarboxylation was the dominant pathway producing n-paraffinic hydrocarbons with one less carbon atom (heptadecane yield up to 94 wt%), while with 5–7.5% formic acid, a hydrodeoxygenation/hydrogenation mechanism was favored producing C18 deoxygenation products octadecanol and octadecane as the main products (yields up to 70 wt%). In contrast, Ru catalysts produced a mixture of C5-C20 (n-and iso-paraffinic) hydrocarbons via decarboxylation, cracking and isomerization (up to 58 wt% C17 yield and total hydrocarbon yield up to 95 wt%) irrespective of formic acid concentration. Kinetic studies showed that the rates of deoxygenation displayed Arrhenius type behavior with apparent activation energies of 134.44 ± 31.36 kJ/mol and 148.92 ± 3.66 kJ/mol, for the 5% Pd/CSigma and 5% Ru/CSigma catalyst, respectively. Furthermore, the experiments with glycerol tristearate, rapeseed oil, sunflower oil, rapeseed biodiesel, and hydrolyzed rapeseed oil produced identical products confirming the versatility of the aforementioned catalytic systems for deoxygenation of C18 feedstocks.

For the first time, a tandem catalytic material namely 5 wt. % Pd/NbOPO 4 was utilized in the depolymerization of wood in supercritical-ethanol under low initial-hydrogen pressure. The experiments were conducted under various experimental conditions, wood fractionation was executed with fresh, and acetone extracted birch. A comprehensive analysis was performed to elucidate the dissolution efficiency and achieved product distribution. The results indicated fresh birch, 34 wt. % of lignin monomer yield with 84 wt. % delignification efficiency were obtained while extracted wood, 35 wt. % of lignin monomer yield with 78 wt. % delignification efficiency was achieved. The total lignin monomer content extracted from the fresh birch is composed of 76.9 wt. % of dimethoxyphenols and 16.5 wt. % of monomers with the guaiacol structure. Among the dimethoxyphenols, major homosyringaldehyde (61.9 wt. %). Where extracted wood, 93.2 wt. % of dimethoxyphenols (63.6 wt. % homosyringaldehyde) and guaiacol-monomers (6.8 wt. %). It was concluded that the depolymerization occurred via breaking of the ether bonds in lignin, including ether hydrolysis by Lewis acid sites over the solid acid catalyst and with subsequent deoxygenation of monophenols over Pd. In addition, an extraction process was proposed to extract the aromatic fraction from the obtained biocrude.