Rhenium-promoted Pt/WO3/ZrO2: an efficient catalyst for aqueous glycerol hydrogenolysis under reduced H2 pressure

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86663-86672 ◽  
Author(s):  
Qing Tong ◽  
Anyi Zong ◽  
Wei Gong ◽  
Lei Yu ◽  
Yining Fan
Keyword(s):  
Catalyst Surface ◽  
Surface Acidity ◽  
Efficient Catalyst ◽  
Glycerol Conversion ◽  
Glycerol Hydrogenolysis

Re improved the dispersion of Pt in Pt/WO3/ZrO2 and enhanced the catalyst surface acidity. Pt–Re/WO3/ZrO2 afforded glycerol conversion >99% and C3 alcohol selectivity >95%. The reactions were performed under reduced H2 pressure.

scholarly journals Glycerol Hydrogenolysis with In Situ Hydrogen Produced via Methanol Steam Reforming: The Promoting Effect of Pd on a Cu/ZnO/Al2O3 Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 110
Author(s):  
Yuanqing Liu ◽  
Chau T. Q. Mai ◽  
Flora T. T. Ng
Keyword(s):  
Steam Reforming ◽  
Catalyst Activity ◽  
Promoting Effect ◽  
Glycerol Conversion ◽  
Glycerol Hydrogenolysis ◽  
Glycerol Dehydration ◽  
Effect Of Pd ◽  
Al2o3 Catalyst ◽  
Reaction Equilibrium

The glycerol hydrogenolysis to produce 1,2-propanediol without using externally supplied hydrogen was investigated using methanol present in crude glycerol to provide in situ hydrogen via its steam reforming reaction. This paper focuses on the promoting effect of Pd on the reactivity of a Cu/Zn/Al2O3 catalyst. Adding 2 wt% Pd onto a Cu/ZnO/Al2O3 catalyst significantly improved the selectivity to 1,2-propanediol from 63.0% to 82.4% and the glycerol conversion from 70.2% to 99.4%. This enhancement on the catalytic activity by Pd is mainly due to the improved hydrogenation of acetol, which is the intermediate formed during the glycerol dehydration. The rapid hydrogenation of acetol can shift the reaction equilibrium of glycerol dehydration forward resulting in a higher glycerol conversion. The improved reducibility of the catalyst by Pd allows the catalyst to be reduced in situ during the reaction preventing any loss of catalyst activity due to any potential oxidation of the catalyst. The catalyst was slightly deactivated when it was firstly recycled resulting in a 5.4% loss of glycerol conversion due to the aggregation of Cu and the deactivation became less noticeable upon further recycling.

Na2HPO4-modified NaY nanocrystallites: efficient catalyst for acrylic acid production through lactic acid dehydration

2014 ◽  
Vol 4 (5) ◽  
pp. 1376-1385 ◽  
Author(s):  
Junfeng Zhang ◽  
Yuling Zhao ◽  
Xinzhen Feng ◽  
Min Pan ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Acrylic Acid ◽  
Acid Production ◽  
Surface Acidity ◽  
Formation Rate ◽  
Structural Features ◽  
Efficient Catalyst ◽  
Acid Yield

An acrylic acid yield of 74.3% and a formation rate of 12.0 mmol gcat−1 h−1 have been achieved at 340 °C by lactic acid dehydration over Na2HPO4-modified NaY nanocrystallites (NaY-n) due to appropriate surface acidity together with the unique structural features of NaY-n.

Ethylene formation by methane dehydrogenation and C–C coupling reaction on a stoichiometric IrO2 (110) surface – a density functional theory investigation

2015 ◽  
Vol 5 (8) ◽  
pp. 4064-4071 ◽  
Author(s):  
T. L. M. Pham ◽  
E. G. Leggesse ◽  
J. C. Jiang
Keyword(s):  
Density Functional ◽  
Catalyst Surface ◽  
Coupling Reaction ◽  
Direct Conversion ◽  
Efficient Catalyst ◽  
Functional Theory ◽  
Elementary Reactions ◽  
Ethylene Formation ◽  
Conversion Of Methane ◽  
Mild Temperature

The capability to activate methane at mild temperature and facilitate all elementary reactions on the catalyst surface is a defining characteristic of an efficient catalyst especially for the direct conversion of methane to ethylene.

Molybdenum oxide modified HZSM-5 catalyst: Surface acidity and catalytic performance for the dehydration of aqueous ethanol

2011 ◽  
Vol 396 (1-2) ◽  
pp. 8-13 ◽  
Author(s):  
Yuwang Han ◽  
Cuiyun Lu ◽  
Dongsheng Xu ◽  
Yelong Zhang ◽  
Yi Hu ◽  
...  
Keyword(s):  
Molybdenum Oxide ◽  
Aqueous Ethanol ◽  
Catalyst Surface ◽  
Surface Acidity ◽  
Catalytic Performance

scholarly journals β-Cyclodextrin-Calcium Complex Intercalated Hydrotalcites as Efficient Catalyst for Transesterification of Glycerol

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1307
Author(s):  
Guanhao Liu ◽  
Jingyi Yang ◽  
Xinru Xu
Keyword(s):  
Value Added ◽  
Nitrogen Adsorption ◽  
Collision Probability ◽  
Molar Ratio ◽  
Glycerol Carbonate ◽  
Efficient Catalyst ◽  
Glycerol Conversion ◽  
Ft Ir ◽  
Adsorption Desorption ◽  
Basic Strength

β-cyclodextrin derivative intercalated MgAl-hydrotalcites (β-CD-Ca/LDH) was synthesized to convert glycerol into high value-added glycerol carbonate(GC) by transesterification of dimethyl carbonate (DMC) and glycerol in this paper. β-cyclodextrin-metal complexes and β-CD-Ca/LDH was characterized by XRD, FT-IR, SEM, XPS and nitrogen adsorption-desorption. The enrichment of organic reactants in the hydrophobic cavity of β-cyclodextrin improved the collision probability of reactants. The intercalation of β-cyclodextrin-calcium complex (β-CD-Ca) increased the pore size and basic strength of catalyst. The experiment results showed that the glycerol conversion was 93.7% and the GC yield was 91.8% catalyzed by β-CD-Ca/LDH when the molar ratio of DMC and glycerol was 3:1, the catalyst dosage was 4 wt.%, the reaction temperature was 75 °C and the reaction time was 100 min while the glycerol conversion was 49.4% and the GC yield was 48.6% catalyzed by MgAl-LDH under the same conditions.

scholarly journals Hydrogenolysis of Glycerol on the ZrO2-TiO2 Supported Pt-WOx Catalyst

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 312 ◽  
Author(s):  
Zhiwen Xi ◽  
Zhe Hong ◽  
Fangtao Huang ◽  
Zhirong Zhu ◽  
Wenzhi Jia ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Self Assembly ◽  
Catalyst Surface ◽  
Acid Sites ◽  
Acidic Properties ◽  
Lewis Acid Sites ◽  
Molar Ratios ◽  
Assembly Method ◽  
Evaporation Induced Self Assembly ◽  
Glycerol Hydrogenolysis

A series of Pt/WOx-ZrO2-TiO2 catalysts with different Ti/Zr molar ratios was prepared by an evaporation induced self-assembly method, and used to efficient hydrogenolysis of glycerol to 1-PO and 1,3-PDO. BET, XRD, Raman, TEM, XPS and Py-IR were employed to characterize the physicochemical properties of the catalysts. The structural and acidic properties of the catalysts were affected by the Ti/Zr ratio of the support ZrO2-TiO2. Two new crystalline phases of ZrTiO4 and Ti2ZrO6 and the amount of acid sites were detected in the Pt/WOx-ZrO2-TiO2 catalysts. 1-PO is dominant in all products of glycerol hydrogenolysis over the supported Pt-WOx catalysts, which is attributed to more Lewis acid sites on the catalyst surface. The Pt/WOx-ZrO2-TiO2 catalyst with a Ti/Zr ratio of 7/3 showed the highest 1,3-PDO yield (25.3%) and 1-PO yield (42.3%), due to its more acid sites including Brønsted and Lewis, and higher concentration of surface Pt0.

Conversion of Glycerol into Value-Added Products Over Cu–Ni Catalyst Supported on γ-Al2O3 and Activated Carbon

2014 ◽  
Vol 12 (1) ◽  
pp. 151-162 ◽  
Author(s):  
Satyanarayana Murty Pudi ◽  
Tarak Mondal ◽  
Prakash Biswas ◽  
Shalini Biswas ◽  
Shishir Sinha
Keyword(s):  
Activated Carbon ◽  
Mixed Oxide ◽  
Bimetallic Catalysts ◽  
Weight Ratio ◽  
Superior Performance ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Glycerol Conversion ◽  
Glycerol Hydrogenolysis ◽  
Acidic Nature

Abstract A series of Cu, Ni monometallic and bimetallic catalysts supported on γ-Al2O3 and activated carbon were synthesized by incipient wetness impregnation method and examined for hydrogenolysis and esterification of glycerol. Hydrogenolysis reaction was carried out in a 250 ml Teflon-coated stainless steel batch reactor at 250°C and 10 bar H2 pressure, whereas esterification of glycerol with acetic acid was carried out at 120°C at atmospheric pressure. The physiochemical properties of the catalysts were investigated by various techniques such as surface area, X-ray diffraction (XRD), NH3-temperature-programmed desorption (TPD). Characterization results dictated that the reduction behavior, acidic nature and the metal support interactions were varied with the support as well as Cu/Ni weight ratio. The XRD results confirmed the formation of mixed oxide Cu0.75Ni0.25 Al2O4 phase in Cu–Ni (3:1)/γ-Al2O3 catalyst. Among the catalysts tested, Cu–Ni bimetallic catalysts showed superior performance as compared to monometallic catalysts in both the reactions. The glycerol hydrogenolysis activity of γ-Al2O3 supported Cu–Ni catalysts was higher than the activated carbon-supported catalysts. 1,2-PDO was obtained as the main hydrogenolysis product independent of the support as well as Cu/Ni weight ratio and its selectivity was in the range of 92.8–98.5%. The acidic nature of γ-Al2O3 and the mixed oxide (Cu0.75Ni0.25Al2O4) phase played an important role for hydrogenolysis activity. Cu–Ni (3:1)/γ-Al2O3 catalyst showed the maximum 1,2-PDO selectivity to 97% with 27% glycerol conversion after a reaction time of 5 h. On the other hand, Cu–Ni(1:3)/C catalyst showed the highest glycerol conversion of 97.4% for esterification and obtained selectivity to monoacetin, diacetin and triacetin were 26.1%, 67.2% and 6.5%, respectively.

TPD study of catalyst surface acidity

1989 ◽  
Vol 39 (1) ◽  
pp. 137-140 ◽  
Author(s):  
A. T. Shakhtakhtinskaya ◽  
Z. M. Mamedova ◽  
Sh. F. Mutallibova ◽  
S. Z. Alieva ◽  
R. G. Mardzhanova
Keyword(s):  
Catalyst Surface ◽  
Surface Acidity

scholarly journals Hydrogenolysis of Glycerol over γ-Al2O3-Supported Iridium Catalyst

2017 ◽  
Vol 61 (4) ◽  
pp. 295
Author(s):  
Tamer S. Ahmed ◽  
Omar Y. Abdelaziz ◽  
George W. Roberts
Keyword(s):  
Hydrogen Pressure ◽  
Reaction Medium ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Solution Ph ◽  
Glycerol Conversion ◽  
The Sustainable Development ◽  
Iridium Catalyst ◽  
Glycerol Hydrogenolysis ◽  
Feed Volume

In recent years, much attention has been focused on the hydrogenolysis of biodiesel derived glycerol to other high value products for the sustainable development and efficient valorization strategies. In the present work, alumina-supported Ir catalyst was prepared by the incipient wetness impregnation method and tested in the glycerol hydrogenolysis reaction. The synthesized catalyst was characterized by neutron activation analysis, N2 physisorption, and H2 chemisorption techniques. The experiments standard conditions were 150 mL feed volume, 0.3 g catalyst, 1500 rpm stirring speed, and 5 wt% glycerol aqueous solution for 4 h. The effects of catalyst amount, temperature, hydrogen pressure, stirring speed, and solution pH on glycerol conversion and selectivity of the principal products obtained were also investigated. The glycerol conversion and the 1,2-propanediol selectivity varied from 4.9% to 22% and from 23.8% to 70.3%, respectively. It was found that the selectivity of 1,2-propanediol increased significantly with the increased alkalinity of the reaction medium.

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