Catalyst For Catalytic Transfer Hydrogenation Research Articles

Heteropolyacids promoted MOF-derived high-performance Co(H4)@C-HPW0.25 catalysts for catalytic transfer hydrogenation of vanillin in mild condition

Catalytic transfer hydrogenation (CTH) was recognized as a promising technique for converting various lignin derivatives to fuels and high-value compounds in heterogeneous systems. Herein, Co@C catalysts with diverse organic ligands, Keggin-type heteropolyacids, acid addition quantities, and metal/organic ligand molar ratios were synthesized via one-pot hydrothermal processes and carbonization methods. The optimized catalyst demonstrated highly efficient active hydrogen generation from isopropanol and the best conversion (100 %) for vanillin (VAN) hydrodeoxygenation (HDO) with 90 % 2-methoxy-4-methylphenol (MMP) yield at 180 °C for one hour under mild conditions of 0 MPa N2 (hydrogen-free circumstance), which were strongly connected to the higher specific surface area (154.45 m2/g), acidic site density (4.67 mmol/g), and stronger metal-P interactions of the Co(H4)@C-HPW0.25 catalyst. The findings in this work provided an advanced thinking for designing high-performance non-noble-metal catalysts that could be applied in the catalytic HDO transformation of various biomass derivatives into green fuel and chemicals under mild circumstances.

Highly active, ultra-low loading single-atom iron catalysts for catalytic transfer hydrogenation

Highly effective and selective noble metal-free catalysts attract significant attention. Here, a single-atom iron catalyst is fabricated by saturated adsorption of trace iron onto zeolitic imidazolate framework-8 (ZIF-8) followed by pyrolysis. Its performance toward catalytic transfer hydrogenation of furfural is comparable to state-of-the-art catalysts and up to four orders higher than other Fe catalysts. Isotopic labeling experiments demonstrate an intermolecular hydride transfer mechanism. First principles simulations, spectroscopic calculations and experiments, and kinetic correlations reveal that the synthesis creates pyrrolic Fe(II)-plN3 as the active center whose flexibility manifested by being pulled out of the plane, enabled by defects, is crucial for collocating the reagents and allowing the chemistry to proceed. The catalyst catalyzes chemoselectively several substrates and possesses a unique trait whereby the chemistry is hindered for more acidic substrates than the hydrogen donors. This work paves the way toward noble-metal free single-atom catalysts for important chemical reactions.

Boehmite-supported CuO as a catalyst for catalytic transfer hydrogenation of 5-hydroxymethylfurfural to 2,5-bis(hydroxymethyl)furan

Boehmite-supported CuO as a catalyst for catalytic transfer hydrogenation of 5-hydroxymethylfurfural to 2,5-bis(hydroxymethyl)furan

Defect-engineered MOF-808 with highly exposed Zr sites as highly efficient catalysts for catalytic transfer hydrogenation of furfural

The highly efficient production of furfuryl alcohol (FFA) from biomass-derived furfural (FFR) is attracting increasing attention due to its wide application in the production of value-added chemicals. Zr-based MOF-808 is promising for liquid catalytic transfer hydrogenation (CTH) of FFR to FFA in terms of possessing a great number of Lewis-acid sites. Herein, a series of defective MOF-808 (Dx-MOF-808) samples were prepared via a competitive coordination-removal strategy by modulating with benzoic acid (HBC). HBC was introduced as the temporary ligand for competing with formal ligand 1,3,5-benzenetricarboxylic acid (H3BTC) to coordinate with metal clusters and then it was removed with methanol to obtain the Dx-MOF-808. The results showed that HBC serves not only as a temporary ligand participating in the synthesis of MOF-808 to obtain defective structure but also as a modulator controlling the particle size by terminating the growth of crystals. By changing the amount of HBC addition, the degree of ligand deficiency and the number of exposed Zr sites can be well regulated. Especially, excellent performance of FFR conversion (99%), FFA selectivity (94.4%) and FFA formation rate (48.6 mmol·g−1·h−1) was achieved over D40-MOF-808 sample with 2-propanol as a hydrogen donor under mild conditions (90 °C, 2 h), ranking it the best among the reported catalysts. Detailed characterizations proved that the high activity of D40-MOF-808 was jointly influenced by the high surface area, the high content of exposed Zr metal sites and ligand deficiency.

Rational synthesis of ruthenium-based metallo-supramolecular polymers as heterogeneous catalysts for catalytic transfer hydrogenation of carbonyl compounds

Ruthenium-based metallo-supramolecular polymers (Ru-MSPs) were synthesized by complexing Ru ions with 1,4-bis(1,10-phenanthrolin-5-yl)benzene ligands for heterogeneously catalytic transfer hydrogenation of carbonyl compounds with formate. The degree of polymerization and the local environment of Ru atoms in Ru-MSP were tailored by tuning the ligand/metal ratio and the synthesis temperature/period. The coordinatively-unsaturated Ru atoms are identified as the active centers in Ru-MSP for carbonyl reduction. Ru-MSP is much more active than Ru-based counterparts including its monomeric analogue, which is attributed to (1) the higher electron density in Ru atoms that facilitates the selective dehydrogenation of formate via C-H dissociation, and (2) the lower LUMO of ligand moieties that activates the carbonyl oxygen via Lewis acid-base interactions. Furthermore, Ru-MSP displays high reusability and capability of catalyzing a wide scope of carbonyl compounds. These findings demonstrate that the rationally-designed polymerization is a promising approach to heterogenize the catalytically active metal complexes with enhanced performance.

Highly effective CoOx for catalytic transfer hydrogenation of plant oil to fatty alcohols

Catalytic non-edible plant oil into high value-added fatty alcohols (FA-OHs) was highly demanded to substitute fossil utilization. Herein, we report a low-cost and highly effective self-supported CoOx catalysts for catalytic transfer hydrogenation (CTH) of plant oil to FA-OHs using isopropanol as hydrogen donor. The small size of selectively exposed crystal planes and homoatomic Co-CoO-Co3O4 interfaces explained for >80% high yield of alcohols observed on Co-DP catalyst at 200 °C in 5 h. The plausible reaction pathway of CTH plant oil based on the detailed investigation of reaction conditions was proposed.

Defect-Engineered Mof-808 with Highly Exposed Zr Sites as Highly Efficient Catalysts for Catalytic Transfer Hydrogenation of Furfural

Defect-Engineered Mof-808 with Highly Exposed Zr Sites as Highly Efficient Catalysts for Catalytic Transfer Hydrogenation of Furfural

Design of a Multifunctional Zirconium-Based Hybrid with Natural Lignocellulose for Transfer Hydrogenation of Furfural to Furfuryl Alcohol

Hydrogenation reduction of furfural (FAL) to furfuryl alcohol (FOL) confirms the requirement of sustainable development of society. The key to realize this transformation is to design a cost-effective and environmental catalyst with both Lewis acid and Lewis base sites. Here, we report the preparation of a multifunctional zirconium-based hybrid (Zr@PS-MSA) using Pennisetum sinese (PS), an annual natural lignocellulose, as a natural organic ligand. The prepared hybrid was used as an efficient catalyst for catalytic transfer hydrogenation (CTH) of FAL to FOL in isopropanol, and a high yield of up to 99.6% was accomplished by manipulating exposed versatile acid–base sites. Further studies indicated that Zr@PS-MSA possessed remarkable cycle stability and could be consecutively run at least 6 times without significant change in the catalytic activity. Mechanistic studies for CTH of FAL to FOL through isotopically labeled 2-propanol-d8 experiments evidently demonstrate FAL reduction via intermolecular hydrogen transfer. More gratifyingly, Zr@PS-MSA can also efficiently catalyze the various biomass-derived carboxides to corresponding alcohols, with yields of up to 92.4%.

Highly Dispersed CoNi Alloy Embedded in N-doped Graphitic Carbon for Catalytic Transfer Hydrogenation of Biomass-derived Furfural.

The development of efficient, stable, and cost-effective heterogeneous catalysts for catalytic transfer hydrogenation (CTH) of biomass-derived furfural (FAL) is highly desired. Herein, series of N-doped graphitic carbon embedded CoNi bimetallic alloy nanoparticles were fabricated and used for the CTH of FAL to value-added furfuryl alcohol (FOL) with renewable isopropanol as hydrogen donor. Intrinsic catalytic activity examination indicated the catalytic performance of Nix Coy @NGC (x:y=1 : 3, 1 : 1, 3 : 1) nanocatalysts were sensitive to their chemical compositions. The optimal Ni1 Co1 @NGC nanocatalyst with Ni/Co mole ratio of 1 : 1 afforded a largest FOL yield of 89.3% with nearly full conversion of FAL. The synergistic effect enabled by bimetallic alloys and the abundant N-based Lewis base sites and surface Co-N active species were revealed based on systematic structural characterization, responsible for the excellent catalytic efficiency of bimetallic Ni1 Co1 @NGC nanocatalyst for CTH of FAL.

A General Route of Using Lignite Depolymerized Derivatives for Catalyst Construction: Insights into the Effects of the Derivative Structures and Solvents.

Depolymerization is an emerging and promising route for the value-added utilization of low-rank coal (LRC) resources, and how to use the complex depolymerized mixtures efficiently is of great importance for this route. In this work, we designed the rational route of using depolymerized mixtures from lignite via ruthenium ion-catalyzed oxidation (RICO) depolymerization directly without complex separation to construct a Zr-based hydrogenation catalyst. The prepared catalyst was applied into the catalytic transfer hydrogenation of biomass-derived carbonyl compounds. Meanwhile, a copper-based oxidation catalyst was also constructed via a similar route to investigate the universality of the proposed route. Special insights were given into how the depolymerized components with different structures influenced the performances of the catalysts. The effects of the solvents used during the catalyst preparation (H2O and DMF) were also studied. The results showed that the proposed route using the depolymerized mixtures from lignite via RICO to construct catalysts was feasible for both Zr-based and Cu-based catalysts. The two catalysts prepared gave high efficiency for their corresponding reaction, i.e., the Zr-based catalyst for catalytic transfer hydrogenation of biomass-derived carbonyl compounds and the Cu-based catalyst for selective oxidation of alcohols into aldehydes. Different depolymerized components contributed differently to the activity of the catalyst, and the solvents during the preparation process could also influence the activity of the catalyst. The depolymerized components and the solvents influenced the activities of the Zr-based catalyst mainly via changing the Zr contents, the microenvironment of Zr4+, and the specific areas of the catalyst.

MOF-derived N-doped carbon composites embedded with Fe/Fe3C nanoparticles as highly chemoselective and stable catalysts for catalytic transfer hydrogenation of nitroarenes

Owing to the competitive hydrogenation of reducible functionalized groups and the complexity of the reaction mechanism, the selective catalytic hydrogenation of nitroarene compounds to value-added amine products is challenging. Herein, we designed and prepared a series of highly efficient iron-based nanocomposites (Fe/Fe3C@NC–T) via direct pyrolysis of the presynthesized NH2–MIL–101(Fe) octahedrons under nitrogen atmosphere, wherein tiny metallic Fe/Fe3C nanoparticles (NPs) were homogeneously inlaid in the N-doped porous carbon matrix. Among the various derived catalysts, Fe/Fe3C@NC–750 exhibited the best performance, with good tolerance to several different functional groups for the catalytic transfer hydrogenation of nitroarenes to anilines using N2H4·H2O as the reductant under mild conditions. This performance was also superior to those of commercial catalysts (Fe, Fe2O3, and Fe3C) and Fe/Fe3C@C–750 without N doping. The synergistic catalysis between the Fe-based NP and N dopant mainly contributed to the excellent catalytic performance of Fe/Fe3C@NC–750. Moreover, the mechanism study revealed that both the direct route and the condensation route were involved in this catalytic reaction system.

High Performance and Sustainable Copper-Modified Hydroxyapatite Catalysts for Catalytic Transfer Hydrogenation of Furfural

Designing and developing non-noble metal-based heterogeneous catalysts have a substantial importance in biomass conversion. Meerwein-Ponndorf-Verley (MPV) reaction is a significant pathway for eco-friendly catalytic transfer hydrogenation (CTH) of biomass derived furfural into furfuryl alcohol. In this work, a series of copper-supported hydroxyapatite (HAp) catalysts with different copper loadings (2–20 wt.%) were prepared by a facile impregnation method and tested in the reduction of furfural to furfuryl alcohol using 2-propanol as a hydrogen donor. The structural and chemical properties of the synthesised catalysts were analysed by using various techniques (XRD, N2 sorption, SEM, TEM, UV-DRS, ICP, FTIR, TPR, TPD-CO2 and N2O titration). The effect of copper loading was found to be significant on the total performance of the catalysts. The results demonstrate that 5CuHAp catalyst possess highly dispersed copper particles and high basicity compared to all other catalysts. Overall, 5CuHAp exhibited highest conversion (96%) and selectivity (100%) at 140 °C at 4 h time on stream. The optimised reaction conditions were also determined to gain the high activity.

Ruthenium on phosphorous-modified alumina as an effective and stable catalyst for catalytic transfer hydrogenation of furfural.

Supported ruthenium was used in the liquid phase catalytic transfer hydrogenation of furfural. To improve the stability of Ru against leaching, phosphorous was introduced on a Ru/Al2O3 based catalyst upon impregnation with ammonium hypophosphite followed by either reduction or calcination to study the effect of phosphorous on the physico-chemical properties of the active phase. Characterization using X-ray diffraction, solid state 31P nuclear magnetic resonance spectroscopy, X-ray absorption spectroscopy, temperature programmed reduction with H2, infrared spectroscopy of pyridine adsorption from the liquid phase and transmission electron microscopy indicated that phosphorous induces a high dispersion of Ru, promotes Ru reducibility and is responsible for the formation of acid species of Brønsted character. As a result, the phosphorous-based catalyst obtained after reduction was more active for catalytic transfer hydrogenation of furfural and more stable against Ru leaching under these conditions than a benchmark Ru catalyst supported on activated carbon.

Hierarchical FAU-Type Hafnosilicate Zeolite as a Robust Lewis Acid Catalyst for Catalytic Transfer Hydrogenation

FAU-type hafnosilicate zeolite with a hierarchical structure (Hf-USY) was constructed through a post-synthesis strategy containing the controlled dealumination of the commercial H-USY zeolite and t...

Hierarchical Flower-like Bimetallic NiCu catalysts for Catalytic Transfer Hydrogenation of Ethyl Levulinate into γ-Valerolactone

Due to fast exploitation and consumption of fossil resources, efficient transformation of renewable biomass would be of vital significance for the production of biofuels and value-added chemicals. ...

Ni nanoparticles on polyaromatic hyperbranched polymer support as a mild, tunable, and sustainable catalyst for catalytic transfer hydrogenation

Hyperbranched polyaromatic polymer (HBP) based on pyridylphenylene dendrimer as a multifunctional monomer was employed as a nanoreactor and a stabilizing matrix for synthesis of catalytic Ni nanoparticles (NPs). The HBP was found to have an effective control over NP size. The Ni NPs synthesized in HBP matrix had diameter between 3 and 4.5 nm with narrow size distribution and were reproducible in several batches. The HBP-encapsulated Ni NPs (Ni-HBP) had a good air stability, high activity, and controlled reactivity in catalytic transfer hydrogenation (CTH) of nitroarenes and alkenes. The catalytic reactions were performed under base-free, heterogeneously-catalyzed conditions without use of high pressure, strong acidic media, or highly flammable hydrogen source. This reduction system showed good tolerance towards hydroxyl, alkyne, or halogen substituents. Moreover, due to mild nature of the catalyst, the reaction may be controlled to selectively reduce only one functional group, leaving another one intact (e.g., nitro-group vs internal alkyne).

Water-born zirconium-based metal organic frameworks as green and effective catalysts for catalytic transfer hydrogenation of levulinic acid to γ-valerolactone: Critical roles of modulators

While zirconium (Zr)-based metal organic frameworks (MOFs) are promising for conversion of levulinic acid (LA) to γ-valerolactone (GVL) through catalytic transform hydrogenation (CTH), these reported Zr MOFs for LA conversion must be synthesized in toxic dimethylformamide (DMF). From the viewpoint of sustainability, it is preferable to avoid usage of DMF-based solvents to prepare these Zr MOFs. As water is a green solvent, the aim of this study is to develop and investigate Zr MOFs, which are prepared in water, for LA conversion to GVL. Specifically, monocarboxylic acids (e.g., formic acid, acetic acid and propanoic acid) are employed as modulators during the preparation of water-born ZrF. The role of modulators is extremely important for the well-developed formation of water-born ZrF. In addition, different monocarboxylic acid modulators also significantly influence the morphology of water-born ZrF; nevertheless, their crystalline structures and acidities are equivalent. As for LA conversion, these water-born modulated ZrF MOFs are validated to successfully convert LA to GVL. Especially, the formic acid-modulated ZrF can exhibit LA conversion = 96%, selectivity for GVL = 98% and yield of GVL = 98%. These water-born modulated ZrF also exhibit even higher catalytic activities than the typical DMF-based ZrF and reported Zr-based MOFs in LA conversion to GVL. These water-born ZrF could be also reused even without regeneration for multiple cyclic LA conversion. These results and findings prove that the water-born ZrF is not only environmentally benign but also more effective for LA conversion to GVL.

Hierarchically constructed NiO with improved performance for catalytic transfer hydrogenation of biomass-derived aldehydes

A 3D nanometer-scaled NiO material with urchin-like structure was prepared via a facile route, and served as a highly efficient and durable catalyst for catalytic transfer hydrogenation of bio-based furfural to furfuryl alcohol using 2-propanol as H-donor and solvent.

Batch versus Continuous Flow Performance of Supported Mono‐ and Bimetallic Nickel Catalysts for Catalytic Transfer Hydrogenation of Furfural in Isopropanol

AbstractFurfural takes an important position in hemicelluloses biorefinery platforms. It can be converted into a wide range of chemicals. One important valorization route is the catalytic hydrogenation. Whereas molecular hydrogen is mostly used in industrial hydrogenation processes, recent studies also showed that alcohols can be used as reductants from which hydrides can be transferred catalytically to furfural. This process is often assisted by the formation of significant amounts of side products, in despite of high yields to the hydrogenolysis product 2‐methylfuran. The present work explores the catalytic behavior in batch and continuous flow of mono‐ and bimetallic nickel catalysts supported on activated carbon for the catalytic transfer hydrogenation of furfural in isopropanol.

Magnetic nickel ferrite nanoparticles as highly durable catalysts for catalytic transfer hydrogenation of bio-based aldehydes

Commercial nickel ferrite (NiFe2O4) nanoparticles are efficient, durable and magnetically recoverable heterogeneous catalysts for catalytic transfer hydrogenation of biomass-derived furfural as well as other aldehydes with 2-propanol as the H-donor forming furfuryl alcohol and various aromatic/allyl/alkenyl alcohols, respectively.