Search

SHCP was active and stable for dehydration of fructose to 5-HMF in DIO/H2O as H2O depressed oligomerization of 5-HMF.

Copper-based catalysts are widely used in methanol synthesis, selective catalytic reduction of NOx, hydrogenation, dehydrogenation and hydrogenolysis reactions. In this work, a series of Cux/Zn3−0.5xMg3−0.5xAl2O9−x catalysts were prepared via the controlled calcination and reduction of hydrotalcite-like structured CuxZn3−0.5xMg3−0.5xAl2(OH)16CO3 precursors. The formation process of Cu2/Zn2Mg2Al2O7 from Cu2Zn2Mg2Al2(OH)16CO3 was characterized via several techniques. Characterizations results indicated that the dispersion of Cu in reduced Cu2/Zn2Mg2Al2O7 reached 79.3%, and it exhibited excellent activity for the dehydrogenation of 1,4-butanediol (1,4-BDO) to γ-butyrolactone (GBL). The detected conversion of 1,4-BDO reached 99.2% with a 99.5% selectivity of GBL at 240 °C, 0.1 MPa and LHSV−1 = 0.13 h, and the calculated productivity of GBL was 7.07 g-GBL/g-cat/h. And Cu2/Zn2Mg2Al2O7 could maintain its activity within 50 h on stream.

Solid acid catalyst plays a crucial role in the petroleum refinery industry and bio-refinery technology. In this work, p-phenolsulfonic acid (PSA) was successfully grafted onto the surface of KH560-modified zirconium phosphate (K-ZrP) in a facile routine. The structure and property of this organic-inorganic combined solid acid PSA/K-ZrP-x were characterized via XRD, FTIR, 13C solid-state NMR, TG, N2 adsorption-desorption, SEM, pyridine-adsorption FTIR and XPS technologies. The characterization results showed that KH560 can bond with ZrP and promote the grafting of PSA on the surface of K-ZrP via the condensation reaction between its epoxy ring and the phenolic hydroxyl group in PSA. Consequently, PSA/K-ZrP-2 exhibited excellent performance and stability in the transesterification between glycerol and methyl acetate among the tested H3PW12O40, Amberlyst-45, HBEA, HZSM-5, ZrP, AlCl3 and FeCl3 catalysts. The calculated conversion of glycerol reached 81.3% with a 97.9% selectivity for monoacetin (MAG) and diacetin (DAG) with a 2.2% dosage of [H+] at 100 °C for 4 h. The highest specific activity of PSA/K-ZrP-2 reached 24028.2 mg-glycerol/g-cat/h in a short reaction time (at 0.17 h), and it could be recycled five times without obvious deactivation.

Selective preparation of unsaturated alcohols via the hydrogenation of C═O in α,β-unsaturated aldehydes is a challenging reaction. In this work, a nanoscale material Pt/UiO-66 catalyst with homogen...

Catalytic combustion is a hot topic both in academic research and in environmental protection. In this work, novel SiO2-supported Pd catalysts (Pd/SiO2-P) were prepared by hydrogen plasma and used ...

Oral administration of medicine faces physiological constraints imposed by the gastrointestinal tract (GIT) and simultaneously causes irritation to GI mucosa, which motivates us to pursue the innovation of a GI drug delivery system. Inspired by the mucosa-nutrient functions of Zinc element and smectite clay, a montmorillonite (MMT)-enveloped zeolitic imidazolate framework (M-ZIF-8) is developed in a successive one-pot fabrication of ZIF-8 encapsulated medicine, and followed MMT coating to yield a core-shell nanoplatform for GI drug delivery. ZIF-8 encapsulated medicines can maintain their intrinsic structure, and MMT layer potentiates mucous-adhesion and optimizes medicine release. Validated in gastritis and colitis models, M-ZIF-8 not only achieves efficient GI delivery of nonsteroidal anti-inflammatory drugs (NSAIDs) for inflammation inhibition, but also reduces the NSAIDs-induced GI irritation, promoting mucosal healing in GIT. Coupled with the facile construction and biocompatibility, M-ZIF-8 shows a significant advancement in GI drug delivery.

Glycerol is one of the most attractive platform chemicals and catalytic upgrading of glycerol to valuable products is of great importance. In the past decade, synthesis of 1,2-propanediol (1,2-PDO) from renewable glycerol has attracted attentions of many scientists. In this review, the performance and recent progress of those typical and popularly reported catalysts, such as Ru-, Pt-based noble metals, Co, Ni, copper-chromite, Cu/ZnO, Cu/Al2O3, Cu/SiO2, Cu/MgO and homogenously dispersed Cu in solid base, in the synthesis of 1,2-PDO from glycerol were summarized in detail. The reaction mechanism over noble metals and Cu-based catalysts were discussed. At the same time, hydrogenolysis of glycerol via catalytic transfer hydrogenation, and the relationship between structure and performance of Cu-based catalyst in continuous hydrogenolysis of glycerol in vapor phase were also compared.

Catalytic transformation of renewable fatty acids into value-added fatty alcohols without the use of gaseous hydrogen is a versatile technique for the utilization of waste cooking oil, where Cu-bas...

Selective oxidation of glycerol with molecular oxygen in base-free aqueous solutions has become a hot topic, as the rapidly increasing production of biodiesel is creating a surplus of glycerol. In this work, an N-doped-carbon-supported core-shell structured Sb@PtSb2 hybrid catalyst was prepared via a facile synthesis route, in which a mixture of glucose, melamine, and SbCl3 (Sb-NC) was pyrolyzed, then impregnated with Pt by immersion in an aqueous solution of H2PtCl6, and further treated in hydrogen flow. Characterization of the catalyst products indicated that introducing SbCl3 can increase the surface area of the binary glucose + melamine pyrolyzed support (NC), and Sb@PtSb2 hybrids could be formed on the surface of an Sb-NC support during hydrogen treatment at 700 °C. It was found that the Sb@PtSb2/NC catalyst was more active for the selective oxidation of glycerol in a base-free aqueous solution than Sb-free NC-supported Pt (Pt/NC). Further characterization also indicated that the promising performance of Sb@PtSb2/NC might be attributed to its enhanced oxygen activation.

Catalytic wet air oxidation (CWAO) is a harmless, cheap and effective technology for the degradation of toxic containments directly to CO

Catalytic transformation of glycerol to value-added products has attracted the attention of scientists all over the world. Among various transformations, selective oxidation of glycerol with molecular oxygen to dihydroxyacetone, glyceric acid, glyceraldehydes, and tartronic acid is challenging both from the viewpoint of academic research and industrial application. Herein, we review the recent progresses in the selective oxidation of glycerol under base-free conditions. Those catalysts widely reported for the selective oxidation of the terminal hydroxyl and secondary hydroxyl groups in glycerol, such as monometallic Au, Pt, and Pd NPs, and bimetallic Au-Pt, Au-Pd, Pt-Bi, Pt-Sb, and Pt-Cu, were compared and discussed in detail. The reaction mechanism over Pt-based catalysts, possible catalyst deactivation, and the corresponding improvements are presented. Further, the recent progresses in the continuous oxidation of glycerol in fixed bed reactors and its excellent selectivity in the formation of dihydroxyacetone are highlighted.

α-zirconium phosphate is widely used as a solid acid catalyst or a catalyst support. In this work, layered crystalline α-zirconium phosphates were synthesized via a facile hydrothermal method and applied in the synthesis of solketal from acetalization of glycerol with acetone. It was found that ZrP-200 (layered α-zirconium phosphate that calcined at 200 °C) is highly active and selective among the tested catalysts. ZrP-200 exhibits both high catalytic efficiency (with an 85.7% conversion of glycerol and a 98.6% selectivity of solketal at 50 °C and 3.0 h) and excellent stability even under mild condition. A series of characterizations results disclose that the performance of ZrP catalysts depends mainly on its surface density of acid sites.

1,3-Propanediol (1,3-PDO) is an important chemical and feedstock in the synthesis of polytrimethylene terephthalate (PTT) resin, but the catalytic production of 1,3-PDO is difficult. In this work, a carbon film encapsulated Co nanoparticle catalyst (Co@NC) was synthesized via pyrolysis of Co2(1,4-benzenedicarboxylic acid)2(triethylenediamine) and tested in the synthesis of 1,3-PDO from glycidol. It was found that this Co@NC catalyst was highly active, selective and stable for this reaction under mild conditions. Characterization results indicated that the formation of 1,3-PDO was sensitive to the adsorbed hydrogen. The selectivity to 1,3-PDO reached its maximum over the Co@NC catalyst as carbon film encapsulation can inhibit the excessive adsorption and activation of H2 molecules, while the adsorbed dissociated hydrogen on naked Co NPs and/or N atoms (in the carbon shell) promoted the formation of propanol.

In this work, different shaped WO3 (rod-like, lamellar and cuboid) supported Pt catalysts were prepared in a facile routine and tested in the selective oxidation of glycerol in base-free aqueous solution. Characterizations indicated that rod-like WO3 supported Pt catalyst (Pt/R-WO3) possesses higher surface area because of the formation of vertical pore channels and highly exposed plane (100), the deposited Pt atoms combined strongly with the terminal W O in rod-like WO3. These properties promoted the adsorption, storage and surface diffusion of oxygen over Pt/R-WO3 which exhibited the excellent activity for the selective oxidation of glycerol. And the higher amount of acid sites on the surface of Pt/R-WO3 enhanced the selectivity of glyceric acid. The calculated turnover frequency of each Pt atom in Pt/R-WO3 reached 946 h–1 at 60 °C.

The rapid rising production of biodiesel has led to a drastic surplus of glycerol, and catalytic conversion of glycerol into value-added products is of great importance. Among of which, solketal, derived from the acetalization of glycerol and acetone, is an important chemical and fuel additive. In this work, a series of solid acid Co[II](Co[III]xAl2−x)O4 catalysts were prepared via controlled decomposition of layered double hydroxide and used in the acetalization of glycerol with acetone. It was found that Co[II](Co[III]xAl2−x)O4 is highly active and selective for this reaction under mild condition. The selectivity of solketal reached 98.6% with a 69.2% conversion of glycerol at 130 °C and 3.0 h over Co[II](Co[III]1.25Al0.75)O4. Characterizations results indicated that the performance of Co[II](Co[III]xAl2−x)O4 depended mainly on the acidity of Co[II](Co[III]xAl2−x)O4, and the conversion of glycerol increased with the amount of strong acid sites.

Catalytic wet air oxidation (CWAO) is a harmless, cheap and effective technology for the degradation of toxic containments directly to CO2 and H2O. In this work, highly dispersed Cu(II)/Cu(I)-N that embedded in the framework of g-C3N4 (Cux-g-C3N4) were synthesized in a facile thermal polymerization method and used in the CWAO of phenols, antibiotics and vitamins. Characterization results confirmed that g-C3N4 formed in the prepared catalyst and copper was chemically coordinated with N in g-C3N4, which inhibited the aggregation of copper. Meanwhile, Cu(II) or Cu(I) in the framework of g-C3N4 was more effective for the degradation of phenol than Cu(0) and CuO, and more than 23 toxic containments could be degraded under mild conditions. The prominent performance of Cu0.1-g-C3N4 for CWAO reaction was discussed on the base of these experiments and it was disclosed that in-situ formed H2O2 might be contributed to the highly activity.

Al2O3-supported Cu and Ni monometallic as well as Cu–Ni bimetallic catalysts were synthesized using a coprecipitation method and studied for the in-situ hydrogenation of furfural (FAL) with isopropanol as the solvent and hydrogen donor. The Cu–Ni bimetallic catalysts showed improved activity toward the production of 2-methylfuran (2-MF) and 2-methyltetrahydrofuran (2-MTHF) over that of monometallic catalysts. The results indicated that isopropanol exhibited better performance than methanol for the in-situ hydrogenation of FAL to produce 2-MF and 2-MTHF under the same conditions. The reaction conditions such as the copper–nickel ratios, catalyst loading amount, reaction temperature, and time were optimized. After the reaction was complete, the supported Cu–Ni bimetallic catalyst could be reused four times without a significant loss in catalytic activity.

Ethanol is a widely used chemical and its primary source is via the fermentation of crops (such as corn, sorghum, rice and barley) or biomass (such as sugarcane). Direct production of ethanol from over-supplying glycerol is of great significance. In this research, we want to report a synthesis route of ethanol from glycerol over a series of Ni-substituted stichtite derived Ni/MgCr2O4 catalysts. The best yield of ethanol reached 0.50 g-ethanol/g-cat/h at 250 °C over Ni2.4/Mg3.7Cr2.0O6.7. The transformation process from Ni-substituted stichtite to Ni/MgCr2O4 catalysts was characterized by TG-DSC, XRD, XPS and TEM. Characterization results inferred that the formation of MgCrO4 in calcined precursor played a crucial role for Ni dispersion and catalytic performance in the production of ethanol. Reaction mechanism for the formation of ethanol from glycerol was proposed.

Carbon-based materials are a popularly-used catalyst support due to their large surface area, high stability, and easy accessibility for reactants, but metal NPs on carbon are prone to sintering and leaching due to weak metal–support interactions. In this work, a 3D carbonaceous material composed of 1D carbon nanotubes sprouting from 2D graphene sheets (denoted Ni@N-CNTs-GS) was synthesized via the direct pyrolysis of mixed agar, melamine, and Ni(en)3(NO3)2. Characterization indicated that the newly formed CNTs were rooted in and anchored by the graphene sheets, and carbon film-encapsulated Ni NPs were dispersed evenly both in the chambers of the CNTs and on the surface of the graphene. It was found that Ni@N-CNTs-GS was active and stable for the selective hydrogenation of nitroarenes to anilines via a direct route.

As a widely used solvent, fuel and intermediate, the demand for ethanol continuously increases. Currently, ethanol is produced via sugar fermentation and hydration of ethylene. It is of great significance to convert abundant glycerol to ethanol. Herein, we report a novel Co/ZnO catalyst with nano-sized Co particles embedded in ZnO plates, which was obtained through calcination and reduction of CoZn-ZIF precursor, and its excellent performance in the synthesis of ethanol from glycerol. The transformation process from CoZn-ZIF to Co/ZnO-ZIF was characterized by TG-DSC, XRD, SEM, TEM and XPS. Characterization results indicated that rhombic dodecahedral composite consisting ZnCo2O4 spinel formed after calcination of CoZn-ZIF precursor, which also led to the formation of small Co particles that embedded in ZnO plates during reduction. Under optimal conditions, the best yield of ethanol reached 1.45 g-ethanol per g-cat per h at 210 °C over Co/ZnO-ZIF. On the basis of a series of controlled experiments, the reaction mechanism for the formation of alcohols from glycerol was proposed.

3-Hydroxybutyraldehyde (3-HBA) is an important intermediate for the manufacture of biodegradable plastics (polyhydroxyalkanoate), and it is of great significance to find an efficient way for the catalytic synthesis of 3-HBA from surplus acetaldehyde. In this work, a series of MgxAlO(x+1.5)-t (t referred to the calcination temperature) solid bases were prepared via the controlled calcination of MgxAl layered double hydroxides with different ratio of Mg/Al and tested in the aldol condensation of acetaldehyde to 3-HBA. Characterization results revealed that the formed MgO particles were embedded in magnesium aluminate spinel (MgAl2O4) in Mg3AlO4.5–1100, which exhibited excellent activity and stability in the continuous liquid flow condensation of acetaldehyde. The detected selectivity of 3-HBA reached 89.0% with a 73.8% conversion of acetaldehyde at 25 °C and WHSV−1 = 2.8 h. Meantime, Mg3AlO4.5–1100 catalyst could retain its activity within 300 h on stream. What's more, the reaction mechanism over Mg3AlO4.5–1100 catalyst was proposed according to the results of several experiments.

Platinum is one of the best catalysts for various applications, but the deactivation of Pt nanoparticles (NPs) during alcohol oxidation is a major barrier to commercialization. In this work, multiwall carbon nanotubes supported carbon film encapsulated Pt NPs (Pt@C-MWCNTs) was synthesized and used in the selective oxidation of ethanol and glycerol in acidic aqueous solution. It was found that Pt@C-MWCNTs exhibited both higher activity and stability than bare Pt NPs. Characterization indicated that carbon film encapsulation can overcome the sintering, leaching and over-oxidation of Pt NPs during the reaction. Moreover, carbon film may also prevent the strong adsorption of organic carboxylic acid on Pt.

Highly dispersed PtCo bimetallic nanoparticles (NPs) were fabricated on reduced graphene oxide (RGO) through microwave irradiation. These PtCo bimetallic NPs showed significantly improved performance for the oxidation of glycerol compared to that of Pt/RGO and Co/RGO. Both the conversion of glycerol (70.2%) and the selectivity of free glyceric acid (GLYA, 85.9%) over PtCo/RGO were obviously higher than that of monometallic Pt/RGO and Co/RGO. Characterizations disclosed that RGO was a superior support for the growth of ultrafine Pt-based NPs, and the dispersion of Pt can be further improved by doping Pt with Co. Moreover, PtCo bimetallic NPs were more aggregation-resisted in comparison to monometallic Pt on the surface of RGO, and it can be reused for 5 runs without obvious deactivation. It was concluded that the strong electrical interaction between Pt and Co in PtCo/RGO might accelerate the oxidation of glycerol, and bimetallic PtCo can hinder the further oxidation of intermediates to C1 byproducts, and thus accelerate the conversion of glycerol and increase the selectivity toward GLYA.

A series of N-doped carbon film coated active carbon (N x C-XC-72) was prepared via direct pyrolysis of mixed XC-72 (a commercial activated carbon), polyvinyl pyrrolidone and urea. Characterizations indicated that the specific area of synthesized N 2.5 C-XC-72 reached 281 m 2 /g and uniform meso pore channels (sized in 4.0 nm) formed. It was found that N x C-XC-72 was an excellent support for the evenly dispersion of Pt compared with raw XC-72. Pt/N x C-XC-72 was active and stable for the selective oxidation of glycerol to glyceric acid in a base-free aqueous solution. The calculated turnover frequency on the basis of surface Pt increased from 573 (in Pt/XC-72) to 706 h − 1 (in Pt/N 2.5 C-XC-72) at 60 °C.

Iron catalysis has attracted a wealth of interdependent research for its abundance, low price, and nontoxicity. Herein, a convenient and stable iron oxide (Fe2O3)-based catalyst, in which active Fe2O3 nanoparticles (NPs) were embedded into carbon films, was prepared via the pyrolysis of iron-polyaniline complexes on carbon particles. The obtained catalyst shows a large surface area, uniform pore channel distribution, with the Fe2O3 NPs homogeneously dispersed across the hybrid material. Scanning electron microscopy, Raman spectroscopy and X-ray diffraction analyses of the catalyst prepared at 900 °C (Fe2O3@G-C-900) and an acid-pretreated commercial activated carbon confirmed that additional carbon materials formed on the pristine carbon particles. Observation of high-resolution transmission electron microscopy images also revealed that the Fe2O3 NPs in the hybrid were encapsulated by a thin carbon film. The Fe2O3@G-C-900 composite was highly active and stable for the direct selective hydrogenation of nitroarenes to anilines under mild conditions, where previously noble metals were required. The synthetic strategy and the structure of the iron oxide-based composite may lead to the advancement of cost-effective and sustainable industrial processes.

Acetalization of glycerol with acetone could convert surplus glycerol into an important fuel additive (solketal). In this work, a stable solid acid catalyst was synthesized in a facile polycondensation of p-phenolsulfonic acid on KH560 modified SiO2 (PSF/K-SiO2) and used in the acetalization of glycerol at room temperature. Characterization results confirmed that PSF/K-SiO2 possessed larger surface area and surface acidity than that of PSF resin (copolymer of p-phenolsulfonic acid and formaldehyde) and non-modified SiO2 supported PSF resin (PSF/SiO2). As a result, PSF/K-SiO2 was extremely active and stable in the acetalization of glycerol. At 25 °C, the detected conversion of glycerol reached 86.3% with a 97.7% selectivity of solketal at 1.5 h. The best yield of solketal over PSF/K-SiO2 could reach 93.1 g-solketal/g-cat/h, and PSF/K-SiO2 could be recycled at least 5 times without obvious decrease in reactivity.

Cu/ZnO catalysts are widely used in industrial production, environmental protection and biorefinery, finding a new and efficient method for the controlled synthesis of Cu/ZnO hybrid is of great importance. In this work, a novel Cu/ZnO catalyst with nano sized ZnO particles dotted on Cu was synthesized via the calcination and reduction of Cu(Zn)-HKUST-1 precursor. The transformation process from Cu(Zn)-HKUST-1 to Cu/ZnO was characterized by TG-DSC, XRD, XPS and TEM. And the performance of final Cu/ZnO catalysts for continuous hydrogenolysis of glycerol was tested in a fixed-bed reactor. It was found that Cu1.1/ZnO catalyst derived from Cu1.1Zn1.9(BTC)2·9.4(H2O) was more active and stable than Cu/ZnO that prepared via solvent-free grinding and co-precipitation. Characterizations results also inferred that the interface between Cu and ZnO played a crucial role on its catalytic performance, and ZnO dotted Cu was more stable than ZnO plate supported Cu particles.

Selective oxidation of glycerol is a hot topic. Increased biodiesel production has led to glycerol oxidation over Au- and Pt-based catalysts being widely studied. However, Pt catalysts suffer from deactivation because of weak metal-support interactions. In this study, multi-walled carbon nanotube (MWCNTs)-pillared nitrogen-doped graphene (NG) was prepared by direct pyrolysis of melamine on MWCNTs, and the synthesized NG-MWCNT composite was used as the support for Pt. Characterization results showed that the surface area (173 m 2 /g) and pore volume of the NG-MWCNT composite were greater than those of bare MWCNTs and the separated melamine pyrolysis product (CN x ). Pt (1.4 ± 0.4 nm) dispersion on the NG-MWCNTs was favorable and the Pt/NG-MWCNT catalyst was highly active and selective in the oxidation of glycerol to glyceric acid (GLYA) in base-free aqueous solution. For example, the conversion of glycerol reached 64.4% with a GLYA selectivity of 81.0%, whereas the conversions of glycerol over Pt/MWCNTs and Pt/CN x were 29.0% and 31.6%, respectively. The unique catalytic activity of the Pt/NG-MWCNTs is attributed to well-dispersed Pt clusters on the NG-MWCNTs and the electron-donating effect of the nitrogen dopant in the NG-MWCNTs.

Mixed MgO–Al2O3 (with different Mg/Al ratio) supported nickel catalysts were prepared via co-precipitation method and used for hydrogenation of levulinic acid to γ-valerolactone under mild condition. Characterization results indicated that mixed MgO–Al2O3 supported Ni catalysts possessed bigger surface area than that of Ni/MgO and Ni/Al2O3, and Ni dispersed highly on the surface of mixed MgO–Al2O3 support. It was found that mixed MgO–Al2O3 supported Ni catalysts were more active and selective for the hydrogenation of levulinic acid to γ-valerolactone than that of Ni/MgO and Ni/Al2O3, and the best yield of γ-valerolactone at 160 °C, 1 h and 3 MPa H2 reached 99.7% over Ni/MgAlO2.5, and Ni/Mg2Al2O5 could be recycled without obvious loss of its initial activity.

Allyl alcohol is a pivotal intermediate and it is of great importance to find a new way for the selective production of allyl alcohol from renewable and surplus glycerol. In this work, we want to report the high performance of CoFe alloy for the direct synthesis of allyl alcohol from glycerol. This alloy catalyst was prepared via the controlled calcination and reduction of CoFe-ZIF precursor. Characterization results indicate that Co can improve the activation of hydrogen and Fe enhances the acidity of prepared CoFe alloy. The activated hydrogen and acid sites in CoFe alloy played a synergistic effect for the selective formation of allyl alcohol directly from glycerol. The selectivity of allyl alcohol remained higher than 68.7 % with a 89.7 % conversion of glycerol at 250 °C, 2 MPa and WHSV = 2.6 h−1. And the reaction mechanism over CoFe alloy was proposed on the basis of controlled experiments.

Layered double hydroxide (LDH) is widely used in adsorption, additive, catalyst precursor and support. In this work, a solvent-free synthesis approach of plate-like Ni–Mg–Al LDH and its application in hydrogenolysis of D-sorbitol was reported. It was found that mainly hexagonal plate-liked LDH crystals (with a diameter of 25–30 nm and a thickness of 7.0–10.5 nm) formed in Ni 3.6 Mg 2.4 Al 2 (OH) 16 CO 3 -SF that synthesized via solvent-free routine. Ni 3.6 Mg 2.4 Al 2 (OH) 16 CO 3 -SF possessed higher crystallinity, bigger specific surface area and stronger basicity than its counterpart that synthesized in traditional coprecipitation method. Bi-functional Ni/solid-base catalyst with homogenously dispersed Ni clusters (with a mean diameter of 3.3 nm) on separated plate-liked Mg 2.4 Al 2 O 5.4 sheets could be prepared after controlled calcination and reduction of Ni 3.6 Mg 2.4 Al 2 (OH) 16 CO 3 -SF. Ni 3.6 /Mg 2.4 Al 2 O 5.4 -SF catalyst was highly active and stable for the hydrogenolysis of D-sorbitol under mild conditions.

The design and facile synthesis of versatile, non-noble metal catalysts with high activity and stability is extremely important for industrial applications. Herein, a novel, simple and one-pot approach of controlled synthesis of graphene encapsulated Fe3C that embedded in carbon nanotubes (denoted as Fe3C@G-CNT) via direct pyrolysis of renewable biomass (glucose, xylitol and sucrose) was reported. Detailed characterizations results indicated that the morphologies and properties of Fe3C@G-CNT composites depended strongly on pyrolysis temperature. Fe3C@G-CNT-700 (prepared at 700 °C) was highly active and stable for the hydrogenation of nitroarenes to anilines at 40 °C, and this catalyst was also active for the selective hydrogenation of CC bond in several compounds. The synthetic strategy, the structure of iron carbide-based composite and the proposed mechanism may open a new avenue for the development of hydrogenation catalysts.

In this work, N-doped reduced graphene oxides (NRGO) was synthesized via a facile urea-hydrothermal treatment of graphene oxide and used as support for ultrafine Pd nanoparticles (NPs). It was found that N in NRGO can improve the dispersion of Pd NPs. NRGO supported Pd catalyst (Pd/NRGO) is highly active and selective for the hydrogenation of CC bond in cinnamaldehyde and hydrogenation of phenol to cyclohexanone under mild conditions. X-ray diffraction, X-ray photoelectron spectra and transmission electron microscopy characterizations confirmed the interaction between NRGO and Pd enhanced with the amount of N atom in NRGO. Raman spectroscopy of adsorbed cinnamaldehyde on Pd/NRGO suggested that NRGO played a positive role in the selective activation of CC bond in cinnamaldehyde.

Reduced graphene oxides supported platinum (Pt/rGO) is extremely active and selective for the production of 2,5-dimethylfuran (DMF) via hydrogenation of 5-hydroxymethylfurfural (HMF) among a series of supported Pt catalysts under mild conditions. The influence of varied reaction parameters, such as solvent, reaction temperature, H2 pressure, and HMF concentration were investigated with respect to the conversion of HMF and the yield of DMF. It was found that the yield of DMF reached 73.2% with a 100% conversion of HMF at 120 °C, 3.0 MPa H2 and 2.0 h.

A series of CuO/ZnO/Al2O3 catalysts were prepared via a direct combustion of Cu nitrate, Zn and Al acetate with citric acid, oxalic acid or urea as fuel. The combustion processes were monitored by thermogravimetry differential scanning calorimeter. Characterizations disclosed that the physicochemical properties of these catalysts depended strongly on the type and amount of fuel. CuO/ZnO/Al2O3 catalyst using citric acid as fuel has a larger surface area, higher CuO dispersion, and the exposed Cu surface area increased with the increasing molar ratio of citric acid/salts in feed. The performances of these catalysts for CO2 hydrogenation to methanol were compared and discussed with their structure.

A series of Cu-substituted hydrocalumite with different content of Cu 2 + were synthesized and used as the precursor of bifunctional Cu/solid base catalysts (Cu x /Ca y AlO y + 1.5 ) in this work. It was found that mainly hydrocalumite formed when the content of Cu 2 + was lower (x x Ca y Al(OH) 2x + 2y + 2 ]NO 3 · n H 2 O). After controlled calcination and hydrogen reduction, Cu dispersed highly in the matrix of Ca y AlO y + 1.5 and the total amount of basic sites reached its maximum in Cu 1.5 /Ca 2.0 AlO 3.5 . These catalysts were active and selective for the hydrogenolysis of glycerol under mild conditions. The calculated specific activity of surface Cu increased with the basicity of catalysts. The detected conversion of glycerol on Cu 1.5 /Ca 2.0 AlO 3.5 reached 75.3% with a 98.1% selectivity towards 1,2-PDO at 180 °C, 2.0 MPa H 2 and 21 h.

Production of C 2 and C 3 polyols from d -sorbitol over Ni/Mg x Al y O x + 1.5y catalysts with different Mg/Al molar ratio were performed under mild conditions. It was found that this reaction proceeded effectively over these bi-functional catalysts prepared via thermal decomposition and reduction of Ni–Mg–Al hydrotalcite-like compounds. The detected conversion of d -sorbitol over Ni/Mg 1.29 Al 0.06 O 1.38 reached 80.7% at 453 K and further increased to 97.0% at 473 K. Characterizations indicate that the performance of these catalysts depended mainly on its surface basicity.

A series of Ca-Al hydrocalumite with different Ca/Al ratios (1–6) were synthesized and used in the transesterification of glycerol with dimethyl carbonate (DMC) to glycerol carbonate (GC) under mild conditions. The calcined Ca-Al hydrocalumites were active with a selectivity toward GC that reached 97% at 93% conversion of glycerol over the sample with Ca/Al = 2 at 70 °C, 3 h, and DMC/glycerol = 3. The glycerol conversion depended mainly on the proportion of strong basic sites in the calcined Ca-Al catalysts. The Ca12Al14O33 phase in the calcined catalysts was stable, but CaO was lost in recycle experiments and thus brought deactivation.

In this communication, N-doped multiwall carbon nanotube (N-MWCNT) supported Pt NPs (1.8 nm) were prepared via a facile routine under microwave irradiation and tested in the selective oxidation of glycerol in an aqueous base-free solution. Characterizations confirmed that N-MWCNTs could improve the dispersion of Pt through strengthened metal-support interactions and donate its electron to metallic Pt. This electron-enriched Pt NPs on the surface of N-MWCNTs is active and stable for the selective oxidation of glycerol.