The Pt-WOx catalyst system has received much attention for its high activity and selectivity in glycerol hydrogenolysis to 1,3-propanediol (1,3-PDO). In this work, the Ga-doped GaWZrOx solid acid supports (GaWZ) with different W contents were prepared, and then Pt/GaWZ catalysts were prepared by the wetness impregnation method. The effects of the W contents on the physicochemical properties and catalytic performance of the Pt/GaWZ catalysts were systematically investigated. CO chemisorption and X-ray photoelectron spectroscopy (XPS) characterizations revealed that the dispersion of Pt on the GaWZ supports first increasesd with the increase in the W content, reached a maximum of 86% on the Pt/GaWZ(10) catalyst with 10% (w) of W, and then decreased at 15% (w) of W. UV-Vis diffuse reflectance (UV-Vis DRS), Fourier transform infrared (FTIR), and XPS characterization showed that the W in the Pt/GaWZ catalysts interacted with the Zr-OH functional groups on the tetragonal phase ZrO2, thus forming mono-dispersed WOx species. When the W content was greater than 7.5% (w), the second layer of the WOx species began to emerge. The mono-dispersed WOx species may be conducive to the high dispersion of Pt. The results of the temperature-programmed desorption of NH3 (NH3-TPD) and pyridine adsorption infrared (Py-IR) characterizations showed that the higher the W content, the higher the amount of the acid on the catalyst, with the simultaneous increase in the amounts of both the Bronsted acids and Lewis acids. In glycerol hydrogenolysis over the Pt/GaWZ catalysts, with the increase in the W content, the glycerol conversion evolved in a volcano-shaped trend, while the selectivity to the target product 1,3-PDO increased monotonically. The highest yield of 1,3-PDO of 47.5% was achieved over the Pt/GaWZ(10) catalyst, and the catalyst also displayed excellent recycling stability. On the basis of the characterization results, we propose that the Pt dispersion and the synergistic interaction between Pt and WOx species determine the activity of the Pt/GaWZ catalysts in glycerol hydrogenolysis, and the Bronsted acid site pertaining to the WOx species is the key to determine the selectivity to 1,3-PDO over the Pt/GaWZ catalysts, as evidenced by the good linear relationship between the 1,3-PDO selectivity and the amount of the Bronsted acid sites.

As a versatile platform molecule, glycerol has been widely studied for the production of high value-added chemicals. In particular, catalytic hydrogenolysis of glycerol to 1,3-propanediol (1,3-PDO) is a highly desired route for glycerol valorization. Herein, hierarchically porous SiO2 nanospheres doped in situ with W (W-HPSN) were synthesized. The effect of the addition of short-chain alcohols (methanol, ethanol, and n-propanol) as co-solvents during the synthesis of W-HPSN on the catalytic performances of the Pt/W-HPSN catalysts in glycerol hydrogenolysis to 1,3-PDO was systematically investigated. The basic physicochemical properties, the chemical states of the active components, and the acidic properties of the catalysts were characterized by a variety of techniques. Compared with the Pt/W-HPSN-H2O catalyst prepared from W-HPSN synthesized only with water as the solvent, when the alcohols were added as the co-solvents, the specific surface area of the catalyst increased to different degrees. And aside from the micropores at 1.4 nm and the mesopores at >2 nm, new micropores appeared at 1.7 nm. In glycerol hydrogenolysis, the catalysts prepared from the W-HPSN synthesized with the addition of alcohols as the co-solvents also displayed improved glycerol conversion and 1,3-PDO selectivity, and the 1,3-PDO yields were in the order of Pt/W- HPSN- Me> Pt/ W-HPSN-Pr>Pt/W-HPSN- Et> Pt/ W-HPSN-H2O. On the best Pt/W-HPSN-Me catalyst synthesized with methanol as the co-solvent, the glycerol conversion and 1,3-PDO selectivity were 88.8% and 56.3%, respectively, in comparison to 64.1% and 40.7%, respectively, on the Pt/W-HPSN-H2O catalyst. Elemental analysis showed that the Pt and W loadings on the Pt/W-HPSN- H2O and Pt/W-HPSN-Me catalysts are identical. The X-ray photoelectron spectroscopy (XPS), Raman, and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) characterizations revealed that the chemical states of the Pt and W species on the Pt/W-HPSN-H2O and Pt/W-HPSN-Me catalysts are similar. CO chemisorption and transmission electron microscopy (TEM) characterizations demonstrated that the Pt particle size on the Pt/W-HPSN-Me catalyst is smaller than that on the Pt/W-HPSN-H2O catalyst. And the cumene cracking reaction detected more in-situ generated Bronsted acid sites on the Pt/W-HPSN-Me catalyst than on the Pt/W-HPSN-H2O catalyst in H-2 atmosphere. On the basis of these characterization results, we propose that smaller Pt particle size and more in-situ generated Bronsted acid sites are conducive to a better catalytic performance of the Pt/W-HPSN catalyst. By further optimization of the composition of the W-HPSN-Me support, at the W/Si molar ratio of 1/320 and under the reaction conditions of 423 K, 4 MPa of H-2 pressure, and reaction time of only 12 h, the Pt/W-HPSN-Me catalyst afforded enhanced glycerol conversion and 1,3-PDO selectivity of 98.7% and 58.8%, respectively, thus giving rise to an outstanding 1,3-PDO yield of 58.0%. This work shows prospect for the HPSN material as an excellent catalyst support for the hydrogenolysis of glycerol to 1,3-PDO.

Using the Raney Fe-Al alloy as the precursor for Fe and Al, and tetrapropylammonium hydroxide (TPAOH) as both the base for the leaching of the alloy and the template for the synthesis of HZSM-5, we synthesized the skeletal Fe core-HZSM-5 shell catalysts (Raney Fe@HZSM-5) via a facile one-pot hydrothermal strategy. The thickness of the zeolite shell was adjusted by varying the hydrothermal time. The catalysts were characterized by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), N-2 physisorption, X-ray powder diffraction (XRD), temperature-programmed desorption of NH3 (NH3-TPD), and scanning electron microscopy (SEM). It was identified that the Raney Fe-Al alloy was more suitable than the rapidly quenched Fe-Al alloy as the precursor to the skeletal Fe core, since the skeletal Fe catalyst alkali-leached from the former produced more long-chain hydrocarbons during the Fischer-Tropsch synthesis (FTS) reaction for successive cracking and isomerization. A complete HZSM-5 shell was obtained only after above 24 h of hydrothermal treatment. With the hydrothermal time from 2 d to 8 d, the thickness of the compact HZSM-5 shell increased from 1.3 mu m to 9.7 mu m, the relative crystallinity increased steadily, while the SiO2/Al2O3 ratio remained essentially constant, and the amount of the acid sites is parallel to the thickness of the zeolite shell. In the FTS reaction using syngas with the H-2/CO molar ratio of 2 and at 543 and 2.0 MPa, the CO conversion and the selectivity to the gasoline fraction (C-5 similar to C-11 hydrocarbons) evolved in a volcanic trend with the shell thickness, suggesting the existence of an optimal amount of the acid sites, while less or more is adverse to the activity and selectivity to the gasoline fraction. The Raney Fe@HZSM-5 catalyst hydrothermally treated for 4 d exhibited the highest CO conversion of 92% and the selectivity to the gasoline fraction of 71%, along with an iso-paraffin to n-paraffin ratio of 1.9. At the n(H-2)/n(CO) ratio of 1, the selectivity to the gasoline fraction and the iso-paraffin to n-paraffin ratio were further improved to 73% and 2.1, respectively, which shows promise for this catalyst to transform the coal- or biomass-derived syngas to high-octane number gasoline.

The mesoporous SBA-15 molecular sieves doped in situ by W with channels parallel to the short axis (W-s-SBA-15) were synthesized by using decane as cosolvent and trimethylbenzene (TMB) as pore-expanding agent, which were used as the supports for the preparation of the Pt/W-s-SBA-15 catalysts. The effect of the loadings of Pt and W on the catalytic performance in glycerol hydrogenolysis to 1,3-propanediol (1,3-PDO) was investigated. The morphology, chemical states of Pt and W, and acidity of the catalysts were systematically characterized by using Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), CO pulsed adsorption, X-ray photoelectron spectroscopy (XPS), Raman, ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS), Fourier transform infrared spectroscopy (FT-IR) and FT-IR of adsorbed pyridine analysis (Py-IR). The BET and TEM results revealed that there are two kinds of pores in the structure: the mesoporous channels parallel to the short axis and honeycomb-like macropores. The Pt dispersion and active surface area calculated from CO chemical adsorption, firstly increased and then decreased with the increase in the Pt and W loadings. The highly dispersed tungsten species were assigned to the single-site WO4 on the basis of the characterization results of Raman, UV-Vis DRS. and FT-IR. The XPS results indicated that the amount of the Pt-O-Si/W linkages and the Pt delta+/(Pt-0 + Pt delta+)ratio are the highest on the 4Pt/W-s-SBA-15(1/480) catalyst which promote the dispersion of the Pt particles on the catalyst surface. With the increase in the loadings of Pt and W, the conversion of glycerol and the conversion of glycerol to liquid products (CTL) increased monotonically, while the selectivity to 1,3-PDO experienced a volcanic-type evolution. At the reaction temperature of 433 K, H-2 pressure of 4.0 MPa, and reaction time of 24 h, the highest yield of 1,3-PDO of 49.0% was resulted on the 4Pt/W-s-SBA-15(1/480) catalyst. It is identified that the conversion of glycerol on the Pt/W-s-SBA-15 catalysts is proportional to the active surface area of Pt on the catalyst, while the small Pt particle size and the strong synergy between Pt and the highly dispersed WO4 species are advantageous to the formation of 1,3-PDO.

A strategy based on galvanic replacement between metallic Zn and Ru salt followed by acid treatment was developed to fabricate supported Ru-Zn/ZrO2 nanocomposite catalysts with controlled contents of Zn for the benzene partial hydrogenation to cyclohexene. The catalysts were systematically characterized by techniques such as extended X-ray absorption fine structure, X-ray photoelectron spectroscopy, and transmission electron microscopy. In benzene partial hydrogenation, with the decrease in the content of Zn, the turnover frequency (TOF) of benzene increased monotonically, whereas the selectivity to cyclohexene evolved in a volcanic trend, passing through a maximum of 72%. Kinetic analysis indicated that with the depletion of Zn, the rate constant for benzene hydrogenation to cyclohexene and that for cyclohexene hydrogenation to cyclohexane increased simultaneously, but the extents of the increments were at variance. It was identified that the ratios of the rate constants were in parallel with the change in the selectivity to cyclohexene, which is attributed to the electronic effect of metallic Zn that modifies the interactions of Ru with benzene and cyclohexene.

We report the modification effects of Pd and Pt on the partial hydrogenation of benzene to cyclohexene over the Ru/ZrO2 catalyst. The Ru/ZrO2, Ru-Pd/ZrO2 and Ru-Pt/ZrO2 catalysts were prepared by the wetness impregnation-chemical reduction method at room temperature. The catalysts were characterized by N2 physisorption, H2 chemisorption, powder X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS), transmission electron microscopy (TEM), X-ray absorption spectroscopy (XAS), and differential scanning calorimetry (DSC). It was identified that the Ru-Pd and Ru-Pt alloys were formed on the Ru-Pd/ZrO2 and Ru-Pt/ZrO2 catalysts, which improved the coordination number of Ru. In the partial hydrogenation of benzene to cyclohexene, while the modification of the Ru/ZrO2 catalyst with Pd or Pt decreased the turnover frequency (TOF) of benzene, the initial selectivity ( S 0) to cyclohexene was improved. The Ru-Pd/ZrO2-0.2 and Ru-Pt/ZrO2-0.15 catalysts with the optimal Pd/Ru and Pt/Ru molar ratios of 0.2 and 0.15 exhibited similar S 0 and the yield of cyclohexene of about 77% and 44%, respectively. On the basis of the characterization results, the modification effects of Pd and Pt on the activity and selectivity of the Ru/ZrO2 catalyst were discussed.

Metal-organic frameworks (MOFs) have attracted enormous research interests not only because of their merits such as high specific surface area, high porosity, and regular pore channels, but also due to their peculiarities of extremely abundant chemical and structural diversity and tunability. In this work, we synthesized MIL-53(Al) and MIL-53(Cr) containing one coordination metal and the novel MIL-53(AlxCr1)(x= 1, 2, 3, and 4) MOFs containing two coordination metals as the supports for the Ru-B/MIL-53 catalysts, which were prepared by the facile impregnation- chemical reduction method. In the challenging partial hydrogenation of benzene to cyclohexene, it is revealed that the Al/Cr ratio had pronounced influences on both the initial hydrogenation rate (r(0)) and the initial selectivity to cyclohexene (S-0). In general, MIL-53 containing a higher fraction of Al affords a higher r(0), while MIL-53 containing both Al and Cr is conducive to a higher S-0 than either MIL-53(Al) or MIL-53(Cr) containing only one coordination metal. On the Ru-B/MIL-53(Al3Cr1) catalyst exhibiting the highest selectivity to cyclohexene, the r(0) and S-0 were 9.2 mmol/(min.g) and 71%, respectively. The best Ru-B/MIL-53(Al3Cr1) catalyst and the Ru-B/MIL-53(Cr) catalyst displaying the lowest selectivity to cyclohexene were comparatively characterized to have an insight into the difference in their catalytic performance. It is found that while both catalysts had similar Ru/B molar ratio, electronic property, and microstructure, the Ru-B/MIL-53(Al3Cr1) catalyst had higher active surface area (Sact), smaller and more highly dispersed Ru-B nanoparticles (NPs), and stronger metal-support interaction than the Ru-B/MIL-53(Cr) catalyst. The smaller Ru-B NPs could not only provide more active sites for the hydrogenation of benzene, but also be beneficial to the formation of cyclohexene. By further optimization of the reaction conditions, at 180 degrees C, H-2 pressure of 5.0 MPa, and using 100 mu L of ethanolamine as the modifier, a cyclohexene yield of 29% was obtained over the Ru- B/ MIL- 53( Al3Cr1) catalyst.

Site-specific deposition of metal nanoparticles (NPs) on metal oxide surfaces is challenging but of particular importance for the development of catalytic materials with improved or new performance. We report here that Ru NPs can be directed to the rutile/anatase junction of P25 TiO2 via a facile wetness impregnation-chemical reduction method at room temperature. In the partial hydrogenation of benzene to cyclohexene, the Ru/P25 catalyst outperformed the Ru NPs supported on phase-pure rutile and anatase as well as physically mixed Ru/rutile and Ru/anatase, both in activity and in selectivity. We identified a unique electron-deficient Ru species (Ru delta+) on the Ru/P25 catalyst originated from the Ru-O linkages connecting the Ru NPs with the rutile/anatase junction. This interfacial Ru delta+ species gave rise to an especially tightly bonding benzene species while lowering the adsorption strength of cyclohexene, thus granting the Ru/P25 catalyst superior activity and unprecedented selectivity toward cyclohexene (initial selectivity 90%). (C) 2015 Elsevier Inc. All rights reserved.

Development of a water–gas shift (WGS) catalyst durable in dynamic shutdown/startup operation is essential to enable residential applications of H 2 ‐powered fuel‐cell systems but remains a conundrum for heterogeneous catalysis. We demonstrate herein that by isomorphic substitution of Zr in the lattice of CeO 2 to increase the acid density of the catalyst, complemented by dosing a small amount of O 2 to realistic reformate to improve the oxidizing potential, the formation of the notorious site‐blocking carbonate species on the Au catalyst can be efficiently retarded. This allows the formation of a highly robust Au/Ce 0.4 Zr 0.6 O 2 WGS catalyst suitable for the challenging shutdown/startup operation in realistic reformate.

A series of metal-organic framework (MOF) materials were synthesized together with the corresponding amorphous Ru-B/MOF catalysts, which were prepared by the impregnation-chemical reduction method. These materials were subsequently evaluated for the first time as catalysts for the partial hydrogenation of benzene to cyclohexene. The results for the initial hydrogenation rate (r(0)) for the different catalysts followed the trend Ru-B/MIL-53(Al)> Ru-B/MIL-53(Al)-NH2> Ru-B/UIO-66(Zr)> Ru-B/ UIO-66(Zr)-NH2> Ru-B/ MIL-53(Cr)> Ru-B/ MIL-101(Cr)>> Ru-B/ MIL-100(Fe), whereas the initial selectivity for cyclohexene (S-0) was of the order of Ru-B/MIL-53(Al)approximate to Ru-B/MIL-53(Cr)>Ru-B/UIO-66(Zr)-NH2>Ru-B/MIL-101(Cr)>Ru-B/MIL-53(Al)-NH2>Ru-B/UIO-66(Zr)approximate to Ru-B/MIL-100(Fe). The Ru-B/MIL-53(Al) catalyst exhibited the highest r(0) and S-0 values of 23mmol center dot min(-1)center dot g(-1) and 72%, respectively. The characterization results demonstrated that the Ru- B amorphous alloy nanoparticles were highly dispersed on MIL-53(Al) with the average diameter of 3.2 nm. In contrast, the Ru-B nanoparticles on MIL-100(Fe) had an average diameter of 46.6 nm. The smaller Ru-B nanoparticles not only provided more active sites for the hydrogenation to occur, but could also be beneficial in the formation of cyclohexene. The reaction conditions were further optimized for the Ru- B/MIL-53(Al) catalyst. At 180 degrees C under a H2 pressure of 5 MPa, a cyclohexene yield of 24% was obtained, highlighting the potential of MOF materials as catalyst supports for the partial hydrogenation of benzene.

Propylene, one of the most demanded commodity chemicals, is obtained overwhelmingly from fossil resources. In view of the diminishing fossil resources and the ongoing climate change, the identification of new efficient and alternative routes for the large-scale production of propylene from biorenewable resources has become essential. Herein, a new selective route for the synthesis of propylene from bio-derived glycerol is demonstrated. The route consists of the formation of 1-propanol (a versatile bulk chemical) as intermediate through hydrogenolysis of glycerol at a high selectivity. A subsequent dehydration produces propylene.

The MgAl2O4 material was synthesized by the hydrothermal method. A series of Ru/MgAl2O4 catalyst samples were prepared using this MgAl2O4 calcined at different temperatures. The catalyst samples were characterized by powder X-ray diffraction, Al-27 solid-state nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, temperature-programmed reduction, temperature-programmed desorption, N-2 physisorption, transmission electron microscopy, and X-ray photoelectron spectroscopy. It was found that the spinel phase readily formed at calcination temperature as low as 773 K. The calcination temperature of MgAl2O4 strongly influenced the structural properties of the catalyst. In the liquid-phase partial hydrogenation of benzene, the Ru/MgAl2O4 strongly influenced the structural properties of the catalyst. In the liquid-phase partial hydrogenation of benzene, the Ru/MgAl2O4 catalyst sample calcined at 1023 K exhibited the hightest cyclohexene selectivity and yield. The maximum cyclohexene yield was 38.5% and the corresponding selectivity was 52.74%. Based on the characterization results, the effect of the calcination temperature of MgAl2O4 on the activity and selectivity of Ru/MgAl2O4 catalyst samples was discussed

The particle size effect on partial hydrogenation of benzene to cyclohexene over Ru/ZrO2 catalysts is reported. Uniform Ru nanoparticles (NPs) with a tunable particle size from 2.4 to 5.4 nm were synthesized by a polyol reduction method and deposited on ZrO2. The catalysts were characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), N2 physisorption, H2 chemisorption, temperature-programmed desorption of H2 (H2-TPD), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It was found that the type of polyol and the concentration of additive (sodium acetate trihydrate) imposed remarkable effect on the particle size of Ru. A distinct particle size effect occurred in partial hydrogenation of benzene. With the size of the Ru NPs increasing, the hydrogenation activity of benzene increased, and the initial selectivity ( S 0) to cyclohexene showed a volcanic-type variation tendency, which revealed that the optimal Ru size for obtaining the highest S 0 is 4.4 nm. The Ru/ZrO2 catalyst reduced by 1,2-propanediol exhibited the highest S 0 (82%) and the yield of cyclohexene (39%). Based on the characterization results, the size effect of Ru on the activity and selectivity is discussed.

The B-doped ZrO2 (B-ZrO2) samples with different B/Zr ratios were synthesized using zirconium oxychloride and boric acid as the precursors. Their crystallographic phase retained as tetragonal ZrO2 after the doping of B; however, the amount of the Lewis acid sites increased from 46.1 mu mol(NH3) g(-1), on ZrO2 to 100.6 mu mol(NH3) g(-1) on B-ZrO2(1/10) with the nominal B/Zr molar ratio of 1/10. The Ru/B-ZrO2 catalysts were then prepared by chemical reduction, and their electronic and structural properties were systematically characterized by spectroscopic techniques. It is identified that the Ru nanoparticles (NPs) supported on these B-ZrO2 samples exhibited similar size, chemical state, and microstructure. In the partial hydrogenation of benzene, the turnover frequency of benzene was linearly proportional to the amount of the acid sites on the supports, whereas the selectivity toward cyclohexene displayed a volcanic evolution passing through a maximum of 88% on the Ru/B-ZrO2(1/15) catalyst. Kinetic analysis indicated that the acid sites improved the rate constants of the benzene to cyclohexene step (k(1)) and the cyclohexene to cyclohexane step (k(2)) to different degrees. The resulting k(1)/k(2) ratio increased from 3.7 x 10(-2) l mol(-1) (Ru/ZrO2) to 4.8 x 10(-2) l mol(-1) (Ru/B-ZrO2(1/15)), and then declined to 4.1 x 10(-2) l mol(-1) (Ru/B-ZrO2(1/10)), which explained the volcanic evolution of the selectivity toward cyclohexene with respect to the acid amount. (C) 2014 Elsevier Inc. All rights reserved.

新形势下对本科物理化学实验课程的培养目标要求越来越高。复旦大学化学系针对物理化学实验教学内容做出了相应的调整，以促进学生探索能力和科研创新能力的提高。

A new efficient method for chemo- and regio-selective semireduction of alkynes using CO/H2O as the hydrogen source catalyzed by gold supported on high surface area TiO2 was developed. A facile and practical synthesis of 1,2-dideuterioalkenes was also realized by using CO/D2O as the reducing agent.

A series of CuZnAl catalysts are synthesized and investigated to study the catalytic performance in the gas-phase hydrogenation of dimethyl oxalate to ethylene glycol. The catalytic activity increases with the increasing of the copper loading, but much higher copper content in the catalysts will lead to the aggregation of the copper particles and cause the deactivation of the catalysts. The influence of calcination temperature is also investigated to probe the microstructure evolution of the catalysts. The catalysts calcinated at low temperature display weak metal-support interaction with poor reducibility and exhibit poor catalytic activity. When the calcination temperature was risen up to temperature higher than 873 K, the mesoporous structure of the support is collapsed or sintered which further lead to the low dispersion of the copper species and poor catalytic property. The catalyst with molar ratio of copper: zinc: aluminium as 1/4/5 (CZA1-4-5) calcinated at 773 K shows the best catalytic performance and can keep the high activity for more than 200 h of time on stream, both the conversion and the selectivity to EG still remain unchanged. (C) 2013 Elsevier B.V. All rights reserved.