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H-Beta zeolites were employed for hexose decarburization to furfural. Excellent performance was achieved over high-Si H-Beta zeolite due to its high B/(B + L) ratio. The synergetic mechanism between *BEA channel and framework-Al is decisive.

Combining glucose dehydration and the subsequent hydrogenation in one pot is a preferable approach for process development as such a method allows in situ generation of the reactive intermediate to undergo further reaction without extra energy-intensive separation. Herein, phosphotungstic acid and various types of titania (anatase, rutile, P25) supported Ru-based catalysts were considered as the dehydration and hydrogenation catalysts, respectively. Modulating the different reactant media (N2, H2), various products were obtained with GBL–H2O as the solvent. A considerable yield (42%) of levulinic acid (LA) and γ-valerolactone (GVL) (40%) were obtained in nitrogen and subsequent hydrogen. Ru/TiO2 (rutile) was the favorable hydrogenation catalyst among the three types of Ru/TiO2. Meanwhile, a certain amount of sorbitol (36%) was obtained in pure hydrogen. The hydrogenation of glucose is more likely to occur than the glucose dehydration. The physicochemical properties of the catalysts were characterized by XRD, BET, TPR, STEM and in situ CO/FT-IR, and the results show that well-dispersed Ru particles are located on the rutile crystallites, which facilitated the hydrogenation of LA. A strong metal support interaction (SMSI) was responsible for the various microstructure properties and the different hydrogenation reactivity. This work allows a better understanding of the reaction paths of glucose conversion.

HZSM-5, Hβ, HY and USY zeolites were applied to the isomerization of glucose. An excellent selectivity (96%) of fructose was achieved, catalyzed by HY zeolite in gamma-butyrolactone/H2O over the fixed bed reactor. Moreover, the glucose isomerization could be carried out for over 480 h under the optimal conditions. High density of Lewis acid (0.27 mmol·g−1) over HY facilitates the intramolecular C2 → C1 H-shift reaction over the glucopyranose ring, which is the rate-determining step during Lewis acid-catalyzed steps of the glucose isomerization. Besides, large porous structure of HY zeolite (7.4 A) facilitates the isomerization of glucose.

The selective synthesis of furfural or hydroxymethylfurfural (HMF) from fructose on single catalyst (Beta zeolite, Hβ) is challenging task. However, in this study, selectivity of Hβ zeolite was discovered easily to tune by solvent effects. Strong solvent effects on the selectivity of fructose conversion were observed in different manners depending on the solvent used. It was shown that the coordinated state of framework aluminum, induced by solvent effects, has a major impact on the selectivity. The solvents with amide group were discovered to induce the reversible tetrahedral-octahedral framework aluminum transformation, but the configuration of aluminum was no influenced by other solvents such as γ-butyrolactone (GBL). Compared with other solvents, the GBL was not able to enhance turnover frequency (TOF) value of reaction but also suppress the degradation of furfural. Interestingly, a considerable yield of furfural (50.25%) was obtained combined with tetrahedral and octahedral framework aluminum active sites in GBL, while high selectivity of HMF (83.3%) was achieved in presence of single tetrahedral framework aluminum over Hβ in NMP.

Novel Cu/ZnO-Al2O3 composites had been constructed and applied in furfural hydrogenation to produce furfuryl alcohol in a fixed-bed reactor. As the result, conversion of FFA over Cu/ZnO catalyst (within 16–24 h TOS) could be improved from 84.9% to 98.0% at 120 °C and 51.4% to 72.1% at 100 °C with a high selectivity of FOL (≈98%) over the novelly constructed Cu/ZnO-Al2O3 catalyst. The role of Al components derived from different precursors like Al(NO3)3, as-prepared Al(OH)3 and pseudo-boehmite had been systemically investigated by various techniques such as XRD, Raman spectroscopy, H2-TPR, N2O titration, XPS, AES experiments and confirmed to be both improving dispersion of copper/zinc species and hindering Cu-ZnO interaction of the aurichalcite derived catalysts. Preparation of the industrial Cu/ZnO-Al2O3 catalysts had been revealed and explained more clearly.

Selective conversion of fructose to fuels and fine chemicals is an important step for biomass utilization. In this paper, direct conversion of fructose to 2,5-dihydroxymethylfuran and 2,5-dimethylfuran was first realized over combined HY zeolite and inexpensive hydrotalcite (HT)-Cu/ZnO/Al2O3 in a fixed-bed reactor. The cooperative effect of HY zeolite and γ-butyrolactone solvent facilitated the dehydration of fructose into 5-hydroxymethylfurfural. By adjusting the hydrogenation temperature for HMF over HT-Cu/ZnO/Al2O3 catalyst, high yields of 2,5-dihydroxymethylfuran (48.2%) at 140 °C and 2,5-dimethylfuran (40.6%) at 240 °C were obtained, respectively.

An efficient process was designed for the synthesis of furfuryl alcohol and 2-methylfuran from xylose using a continuous fixed-bed reactor over a catalyst combining Hβ zeolite and Cu/ZnO/Al2 O3 in γ-butyrolactone (GBL)/water as solvent. The cooperative effect of Hβ zeolite and GBL facilitated the dehydration of xylose and enhanced largely the furfural yield. The production of furfuryl alcohol and 2-methylfuran can be simply tuned by changing the hydrogenation temperature for furfural over the Cu/ZnO/Al2 O3 catalyst. The yield for furfuryl alcohol reached 87.2 % at 150 °C whereas a yield of 86.8 % was achieved for 2-methylfuran at 190 °C.

An aqueous suspension of WO3/poly(4-(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl-methoxy)-1-butanesulfonic acid) (PEDTS) hybrid nanoparticles (NPs) is prepared by air-assisted oxidative polymerization and simultaneous attachment of PEDTS on WO3-NPs, and used for electrochromic (EC) film fabrication via air-brush spraying. The hybrid EC device exhibits enhanced EC properties compared to the ones based on WO3-NP or PEDTS alone.

Cu/SiO2 catalysts were synthesized by different methods, which greatly influenced their texture and the catalytic performance. The AE-Cu/SiO2 catalyst was prepared via the ammonia evaporation method and showed a 95.5% yield for 2-methylfuran (a promising fuel additive) because of the cooperative effects of surface Cu0, Cu+ species and acid sites, which respectively stemmed from the reduction of highly dispersed CuO species, copper species that fiercely interacted with the support SiO2, and the special structure. The ammonia evaporation method favored the formation of a copper phyllosilicate phase with a lamellar structure, which could provide a large number of Cu nanoparticles and acid sites and further improve the activity and selectivity. Crucially, the stability of the AE-Cu/SiO2 catalyst (>210 h) was also significantly improved due to the enhanced copper–silicon interactions, which could immobilize copper particles and resist the fast transmigration (aggregation and loss) of copper particles in the thermal treatment process. In contrast, the CP-Cu/SiO2 catalyst was synthesized via the conventional precipitation method and presented poor activity and stability toward 2-methylfuran because of large copper particles, severe aggregation and a loss of copper species during reaction. Compared with the conventional CP-Cu/SiO2 catalyst, the use of the AE-Cu/SiO2 catalyst in the synthesis of the biofuel 2-methylfuran could not only improve the yield of the desired product, but also decrease by at least 20 °C the reaction temperature which is propitious for prolonging the lifetime of the Cu/SiO2 catalyst.

A series of Pd/Al2O3 catalysts with different alkali earth metals (Mg, Ca, Sr, Ba) and varying Sr loadings (1.8, 3.5, 5.3, 7 and 8.8 wt%) were investigated for 5-hydroxymethylfurfural (HMF) decarbonylation. The alkali earth metal and content were demonstrated to have profound influences on the metal dispersion, electron density of the metal, acid–base properties of the catalyst, and catalytic performance. The Pd3Sr/Al2O3 catalyst exhibited the highest initial activity and furfuryl alcohol selectivity, achieving a yield of 92%. The key to high decarbonylation selectivity is the suppression of hydrogenolysis and etherification side reactions through the attenuation of the acidity of catalysts. Successful catalytic activity not only lies in the increased metallic surface area, but is also affected by the adsorption properties of the carbonyl group and the poisoning CO produced. The catalytic activity is linearly correlated to the surface metallic area at low modifier loading over PdM/Al2O3 catalysts. But along with further increased metallic surface area over PdXSr/Al2O3, HMF conversion initially increased, reaching a plateau over Pd3Sr/Al2O3 and then decreased with increasing Sr loading. A synergistic effect between the Sr species and metallic Pd was proposed, which promoted the migration of carbonyl adsorption from the support to the surface Pd through the electron donation of Sr species to Al2O3 and metallic Pd.

Selective hydrogenation of 5-hydroxymethylfurfural (HMF) is of great importance for future energy and chemical supply. Herein, we propose for the first time that non-noble Ni-Al2O3 catalysts derived from hydrotalcite-like compounds can efficiently and selectively convert HMF into 2,5-dimethylfuran (DMF), 2,5-dimethyltetrahydrofuran (DMTHF) and 2,5-dihydroxymethyltetrahydrofuran (DHMTHF). Homogeneous elemental distributions of the hydrotalcite-like precursor facilitate good dispersion of Ni and Al2O3 species and strong interaction between them over the resulting catalysts. The catalysts therefore exhibited superior reactivity. Through fine modulation of surface metal–acid bifunctional sites and control of reaction conditions, high yields of DMF (91.5%), DMTHF (97.4%) and DHMTHF (96.2%) can be diversely achieved. The results demonstrate the feasibility of Ni catalysts for selective hydrogenation of CO, CC and C–O bonds, which have great potential for biomass utilization.

Selective conversion of 5-hydroxymethylfurfural (HMF) can produce sustainable fuels and chemicals. Herein, Cu–ZnO catalysts derived from minerals (malachite, rosasite and aurichalcite) were employed for selective hydrogenation of HMF for the first time. High yields of 2,5-dihydroxymethylfuran (~99.1%) and 2,5-dimethylfuran (~91.8%) were obtained tunably over the catalyst with a Cu/Zn molar ratio of 2, due to the well-dispersed metal sites tailored by mineral precursors, well-controlled surface sites and optimized reaction conditions. The relationship between catalytic performance and catalyst properties was elucidated by characterization based on the composition and the structural and surface properties, and catalytic tests. The catalyst can also be extended to selective hydrogenation of other bio-derived molecules (furfural and 5-methylfurfural) to target products. The construction of mineral-derived Cu–ZnO catalysts and the revelation of the structure–performance relationship can be applied to further rational design and functionalization of non-noble Cu catalysts for selective conversion of bio-derived compounds.

Ethanol synthesis from syngas via dimethyl oxalate (DMO) hydrogenation is of crucial importance for environment- and energy-related applications. Herein, we designed the bifunctional Cu nanoparticle (NP) inlaid mesoporous Al2O3 catalyst and first applied it to ethanol synthesis with high efficiency. The catalyst was made based on the spatial restriction strategy by pinning the Cu NPs on mesoporous Al2O3 to conquer the sintering problem and facilitate the stability (>200 h at 270 °C), which has potential values in high-temperature and exothermic reactions. The plentiful pores, highly exposed and properly assembled Cu-acid sites, furnished the catalyst with high ethanol yield (∼94.9%). A structure-sensitive behavior that the intrinsic activity increases with the decreasing NP size was discussed. It was attributed to the change in metal–acid interfacial sites, morphology, and electronic structure and balance of surface Cu0–Cu+ species. The mechanism for DMO hydrogenation to ethanol involving activation of C═...

An efficient and selective synthesis of unsymmetrical tetrahydrofurfuryl carbonate and other organic carbonates was realized in the liquid phase transesterification dimethyl carbonate (DMC) with alcohols over the K 2 CO 3 /ZrO 2 catalyst. Compared with MgO, CaO, MgAl-HDT, ZrO 2 , and CsF/α-Al 2 O 3 , the K 2 CO 3 /ZrO 2 catalyst with lower basicity displayed a significantly higher activity. The results of FT-IR, XPS and CO 2 -TPD suggested that the carboxylate species on the surface of the K 2 CO 3 /ZrO 2 catalyst were the active sites for the DMC transesterification. Other K 2 CO 3 supported TiO 2 , SiO 2 and Al 2 O 3 catalysts showed a rather low catalytic activity due to the lack of carboxylate species.

The catalytic performances of co-precipitated copper catalysts supported on SiO2, ZrO2 and Al2O3 for dimethyl oxalate hydrogenation were studied. Systematic characterizations showed that copper species formed on different supports as a result of different metal-support interactions influenced the activity and stability, while the nature of supports was closely related to the products distribution in dimethyl oxalate hydrogenation. Mainly large Cu particles were detected over Cu/SiO2 catalyst which exhibited a low activity and stability. For the Cu/ZrO2 catalyst, the highly dispersed Cu particles and the strong metal-support interaction are in favor of its superior activity and stability. Among the catalysts, Cu/SiO2 exhibited maximum ethylene glycol selectivity while Cu/Al2O3 showed a 2-methoxyethanol selectivity of 53.5% in methanol solvent. As tuning the solvent into 1,4-dioxane, an ethanol yield up to 95.5% was received in Cu/Al2O3. The significant difference of selectivity is mainly due to the acidity of the catalysts. Thus, the highly selective synthesis of ethylene glycol and ethanol could be realized by regulating the supports and solvents, and a proper reaction route was proposed.

The promotion effects of alkaline earth metals (Mg, Ca, Sr, Ba) on the catalytic property of the Cu/SiO 2 catalyst for the gas phase dehydrogenation of 1,4-butanediol were investigated. The addition of Ca, Sr or Ba to the Cu/SiO 2 catalyst resulted in the improvements of the catalytic activity and the γ-butyrolactone selectivity, and the Cu-Ba/SiO 2 catalyst gave 99.6% yield of γ-butyrolactone even after 900 h running. The catalysts were prepared by co-impregnation and characterized by N 2 physisorption, X-ray diffraction (XRD), SEM, TEM, H 2 -temperature programmed reduction (H 2 -TPR), N 2 O-decomposition, ammonia temperature-programmed desorption (NH 3 -TPD), CO 2 -TPD, XPS, and FTIR spectroscopy of adsorbed pyridine and CO. On the base of the experimental results, two types of copper species on the reduced catalyst were proposed. The Cu° account for the dehydrogenation of 1,4-butanediol, while the electropositive copper species (Cu + ) is suggested to be the strong Lewis acid site to catalyze side reactions. The selectivity of γ-butyrolactone was increased with the increasing of the Cu 0 /Cu + ratio, and the yield of γ-butyrolactone was increased with copper surface area. The main byproduct 2,3-dihydrofuran may be formed from 1,4-butanediol by the metal/acid–base concerted catalysis.

BACKGROUND: Catalytic upgrading of fermentation-derived succinic acid or its derivates (succinic acid esters and succinic anhydride) to value added chemicals has received great attention recently. The aim of this work is to provide a process for the production of tetrahydrofuran from succinic acid esters. RESULTS: The hydrogenolysis of biomass-derived diethyl succinate was investigated over CuOZnO and CuOZnO/solid acid (HY, HZSM-5, SAPO-11 and Al2O3) catalysts in a fixed-bed reactor. Over CuOZnO, gamma-butyrolactone and 1,4-butanediol can be selectively produced under appropriate reaction conditions, while the selectivity of tetrahydrofuran is relatively low due to the weak acidity of CuOZnO. Over CuOZnO/HZSM, both the formed 1,4-butanediol and ethanol can be further converted to tetrahydrofuran and diethyl ether, while tetrahydrofuran is selectively produced over CuOZnO/HY. CuOZnO/Al2O3 and CuOZnO/SAPO exhibit slight improvements in terms of selectivity to tetrahydrofuran when compared with CuOZnO. CONCLUSION: CuOZnO/HY is an appropriate catalyst to produce tetrahydrofuran from biomass-derived diethyl succinate with high activity, selectivity and stability. Furthermore, Bronsted acid sites with appropriate acid strength are responsible for the selective formation of tetrahydrofuran under the applied reaction conditions. Copyright © 2010 Society of Chemical Industry

The reactivity of biomass-derived diethyl succinate and its main reaction intermediates was separately investigated in a fixed-bed reactor over CuO/ZnO catalyst, and some interesting results were obtained. Ethyl 4-hydroxybutyl succinate as an intermediate of diethyl succinate hydrogenation reaction was first detected, and it could be converted to 1,4-butanediol or polyesters. Additionally, propanol and butanol are mainly derived from 1,4-butanediol rather than gamma-butyrolactone. A comprehensive reaction pathway for the hydrogenation of diethyl succinate is proposed, which is significant for the design of new catalytic formulations. A CuO/ZnO + HY admixed catalyst exhibiting excellent performance was prepared according to the proposed reaction pathway.

Using a SiO2 supported copper and H4SiW12O40 catalyst, it is demonstrated that glycerol can be directly converted to 1,3-Propanediol (1,3-PD) through vapor-phase process under pressure below 0.54 MPa, without employing environmentally harmful organic solvent. The formation of 1,3-PD is proved to proceed through the designed reaction pathway: (step 1) dehydration of glycerol to 3-hydroxypropanal on acid site of supported H4SiW12O40 (step 2) hydrogenation of 3-hydroxypropanal on supported copper metal. The effect of temperature, weight hourly space velocity, pressure, and initial water content was investigated to obtain the optimum conditions. The glycerol conversion and products distribution greatly depended on these factors. Both the 1,3-PD and 1,2-Propanediol selectivity improved with increasing hydrogen pressure. At 210 °C, 0.54 MPa and 83.4% conversion, the selectivity of 1,3-PD was up to 32.1%, together with a 22.2% selectivity of 1,2-Propanediol. The cyclic acetal, an important kind of byproducts, was identified by Gas Chromatogram–Mass Spectrometer (GC–MS).

One-step direct conversion of biomass-derived furfural to 2-methyltetrahydrofuran was realized under atmospheric pressure over a dual solid catalyst based on two-stage-packed Cu-Pd in a reactor; this is the first report that one-step conversion of furfural resulted in high yield of 2-methyltetrahydrofuran (97.1 %) under atmospheric pressure. This strategy provided a successive hydrogenation process, which avoids high H2 pressure, uses the reactor efficiently, and eliminates the product-separation step. Therefore, it could enhance the overall efficiency as a result of low cost and high yield.

Selective detection of cyanide anions is realized via electrofluorochromism of a benzothiadiazole-containing conjugated copolymer because oxidative fluorescence quenching induced by positive potentials can be significantly weakened by interaction between nucleophilic cyanide and electron-deficient benzothiadiazole. ASTAR (Agency for Sci., Tech. and Research, S’pore) Accepted Version

The aqueous-phase hydrogenolysis of furfuryl alcohol (FFA) to 1,2-pentanediol (1,2-PeD) was carried out on a series of supported Ru catalysts and MnOx supported Pt, Pd and Rh catalysts. The Ru/MnOx catalysts showed high selectivity for 1,2-PeD, while the Pd and Rh catalysts displayed high selectivity for tetrahydrofurfuryl alcohol. The function of MnOx, the effects of solvent, temperature, H2 pressure and reaction time were further investigated. The support MnOx in the Ru/MnOx catalysts not only suppressed the polymerization of the FFA, but also enhanced the 1,2-PeD selectivity. Low pressure and high temperature favoured the generation of 1,2-PeD, and water significantly enhanced the reaction rate. At 150 °C, 1.5 MPa, the yield of 1,2-PeD was up to 42.1% over the Ru/MnOx catalyst. The proposed mechanism for FFA hydrogenolysis in aqueous medium over the Ru/MnOx catalyst is suggested to occur via a partially hydrogenated intermediate.