Catalyst Development for the Hydrogenolysis of Biomass-Derived Chemicals to Value-Added Ones

Hydrogenolysis of alginic acid over mono and bimetallic ruthenium/nickel supported on activated carbon catalysts with basic promoters

Hydrogenolysis of alginic acid, derived from macroalgae, was performed over Ru–Ni supported on activated carbon catalyst using NaOH as basic promoter to produce glycols.

Influence of Boron, Tungsten and Molybdenum Modifiers on Zirconia Based Pt Catalyst for Glycerol Valorization

The influence of boron, tungsten and molybdenum modifiers on zirconia-based Pt catalyst was studied for glycerol valorization. Zirconia modified supports were prepared by impregnation of ZrO₂ with either boric, silicontungstic or phosphomolybdic acids to obtain supports with enhanced Brönsted acidic properties. The modified supports were subsequently impregnated with chloroplatinic acid to obtain Pt-based catalysts. Pt incorporation resulted in the increase in Lewis acidity of the solids, being more significant for the Pt//W/ZrO₂ catalyst. Reduced Pt catalysts were tested for the liquid-phase glycerol hydrogenolysis, observing a synergistic effect between catalyst acid sites and metal function that proved to be crucial in glycerol hydrogenolysis. The Pt//W/ZrO₂ catalyst was the most active catalyst in this reaction, being the only leading to 1,3-PDO (45% sel., 160 °C) while Pt//Mo/ZrO₂ is the best option for 1,2-PDO (49% sel., 180 °C). Reusability studies carried out for Pt//W/ZrO₂ showed that catalytic activity dropped after the first use, remaining constant for the second and subsequent ones. Selectivity to reaction products also changes during reuses. Therefore, the selectivity to 1,2 PDO increases in the first reuse in detriment to the selectivity to n-propanol whereas the selectivity to 1,3-PDO remains constant along the uses. This behavior could be associated to the lixiviation of W species and/or catalyst fouling during reaction runs.

Facile ring-opening of THF at a lithium center induced by a pendant Si-H bond and BPh3

The macrocyclic polyamine 1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane [LH = (Me₃TACD)H] formed adducts with tetramethyl-silazides [M{N(SiHMe₂)₂}] (M = Li, Na, K) of light alkali metals. Upon heating, intramolecular dehydrocoupling occurred to give [M{(L)SiMe₂N(SiHMe₂)}]. BPh₃ induced facile ring-opening of THF when reacted with [Li{(L)SiMe₂N(SiHMe₂)}].

Theoretical studies on the electronic structures and photoelectron spectra of tri-rhenium oxide clusters: Re3O(n)(-) and Re3O(n) (n=1-6)

Density functional theory (DFT) calculations are performed to study the structural and electronic properties of tri-rhenium oxide clusters Re3On(-/0) (n=1-6). Generalized Koopmans' theorem is applied to predict the vertical detachment energies (VDEs) and simulate the photoelectron spectra (PES). Theoretical calculations at the B3LYP level are carried out to search for the global minima for both the anions and the neutrals. For the anions, the first two O atoms prefer the same corner position of a Re3 triangle. Whereas, Re3O3(-) possesses a C2v symmetry with one bridging and two terminal O atoms. The next three O atoms (n=4-6) are adding sequentially on the basis of Re3O3(-) motif, i.e., adding one terminal O atom for Re3O4(-), one terminal and one bridging O atoms for Re3O5(-), and one terminal and two bridging O atoms for Re3O6(-), respectively. Their corresponding neutral species are similar to the anions in geometry except Re3O4 and Re3O5. Molecular orbital analyses are employed to investigate the chemical bonding and structural evolution in these tri-rhenium oxide clusters.

Catalytic CO2conversion to organic carbonates with alcohols in combination with dehydration system

This perspective highlights the direct synthesis of organic carbonates from CO₂and alcohols combined with dehydration systems.

Efficient Ru–Fe catalyzed selective hydrogenolysis of carboxylic acids to alcoholic chemicals

A bimetallic nanocatalyst Ru–Fe/SBA-15 shows remarkable ability to catalyze selective hydrogenolysis of carboxylic acids to alcoholic chemicals and the optimized catalyst is stable for the hydrogenolysis of acetic acid to ethanol with high catalytic performance for 300 h.

Performance and characterization of rhenium-modified Rh–Ir alloy catalyst for one-pot conversion of furfural into 1,5-pentanediol

Rh–Ir–ReO_x/SiO₂ catalyst with ReO_x-modified Ir–Rh alloy particles can convert furfural to 1,5-PeD in high yield.

Synthesis of high-quality diesel with furfural and 2-methylfuran from hemicellulose

Hydroxyalkylation-alkylation (HAA) coupled with hydrodeoxygenation is a promising route for the synthesis of renewable high-quality diesel or jet fuel. In this work, a series of solid-acid catalysts were firstly used for HAA between lignocellulose-derived furan and carbonyl compounds. Among the investigated catalysts, Nafion-212 resin demonstrated the highest activity and stability. Owing to the high activity of the reactants and the advantage in industrial integration, the HAA of 2-methylfuran (2-MF) and furfural can be considered as a prospective route in future applications. Catalyst loading, reaction temperature, and time had evident effects on the HAA of 2-MF and furfural over Nafion-212 resin. Finally, the HAA product of 2-MF and furfural was hydrogenated over a Pd/C catalyst and hydrodeoxygenated over Pt-loaded solid-acid catalysts. Pt/zirconium phosphate (Pt/ZrP) was found to be the best catalyst for hydrodeoxygenation. Over the 4 % Pt/ZrP catalyst, a 94 % carbon yield of diesel and 75 % carbon yield of C15 hydrocarbons (with 6-butylundecane as the major component) was achieved.