504-63-2Relevant articles and documents
Selective Hydrogenolysis of Glycerol to 1,3-Propanediol over Rhenium-Oxide-Modified Iridium Nanoparticles Coating Rutile Titania Support
Liu, Lujie,Asano, Takehiro,Nakagawa, Yoshinao,Tamura, Masazumi,Okumura, Kazu,Tomishige, Keiichi
, p. 10913 - 10930 (2019)
The effect of support in Ir-ReOx catalysts for glycerol hydrogenolysis to 1,3-propanediol was investigated. Rutile TiO2 support showed high activity, even higher than previously reported SiO2 support. Anatase TiO2, C, ZrO2, CeO2, Al2O3, and MgO supports showed very low activity of supported Ir-ReOx pairs. Higher Ir-based 1,3-propanediol productivity of Ir-ReOx/rutile catalyst was obtained at the initial stage even with lower Re/Ir ratio (typical Ir loading amount, 4 wt %, nominal ratio of 0.25; actual ratio of 0.24) without addition of H2SO4 than that of Ir-ReOx/SiO2. The 1,3-propanediol productivity over Ir-ReOx catalysts showed dependency on catalyst compositions (metal loading amount), and the relationship between catalyst structure and activity was further established over Ir-ReOx/rutile. Relatively high Ir loading amount in comparison with small surface area (6 wt %, on 6 m2 g-1 rutile TiO2) showed the highest activity (Ir-based activity). From combined characterization results altogether (TPR, TEM, XPS, XAS, CO adsorption, CO FT-IR) with a kinetics study, the Ir metal particles interacted with the partially oxidized ReOx cluster (average valence of Re: +3) almost totally covering the surface of rutile TiO2 particles, and the active site was the Ir-ReOx interface. Small amounts of Ir species were incompletely reduced; however, such IrOx species as well as rutile TiO2 support were not directly involved in glycerol hydrogenolysis. The role of rutile support was regarded as providing a unique environment for stabilization of uniform and small Ir-ReOx particles with very high surface density on rutile TiO2, which increased the number of active sites per Re amount.
Aqueous-phase deoxygenation of glycerol to 1,3-propanediol over Pt/WO 3/ZrO2 catalysts in a fixed-bed reactor
Qin, Li-Zhen,Song, Min-Jie,Chen, Chang-Lin
, p. 1466 - 1472 (2010)
Deoxygenation of glycerol in aqueous medium catalyzed by Pt/WO 3/ZrO2 at relatively low temperatures (110-140°C) under hydrogen pressure range from 2 to 5 MPa in a fixed-bed continuous-flow reactor gives 1,3-propanediol (1,3-PDO) and n-propanol (n-PrOH) as the predominant products, indicating high selectivity for deoxygenation of the secondary hydroxyl group over the primary hydroxyl groups of the glycerol. The optimum catalyst was prepared by calcination of WO3/ZrO2 at 700°C and loading of 3.0 wt% Pt with W content of 10 wt%. The effect of reaction temperature, hydrogen pressure and initial water content were evaluated to find the optimum reaction conditions. The glycerol conversion and the yield of 1,3-PDO greatly depended on these factors. At 130°C, 4 MPa and 70.2% conversion, the yield of 1,3-PDO was up to 32.0% (1,3-PDO/1,2-PDO = 17.7). The proposed mechanism for glycerol deoxygenation in aqueous medium over Pt/WO 3/ZrO2 is an ionic pathway involving proton and hydride ion transfer steps.
Discovering positively charged Pt for enhanced hydrogenolysis of glycerol to 1,3-propanediol
Zhao, Binbin,Liang, Yu,Liu, Lei,He, Qian,Dong, Jinxiang
, p. 8254 - 8259 (2020)
Atomically-dispersed Pt supported on WOx-modified tantalum oxide was developed as a highly active catalyst for selective hydrogenolysis of glycerol, with the productivity of 30.80 g gPt-1 h-1 toward 1,3-propanediol. The WOx species pre-deposited on T-Ta2O5 were found to assist the atomic dispersion of platinum. The WOx-stabilized Ptδ+ species adsorb hydrogen easily and facilitate the hydrogen heterolytic dissociation, which significantly enhances the capability of in situ generated Br?nsted acid sites and the hydrogenation activity. This provides a new strategy for developing bi-functional catalysts for a broad range of hydrogen and acid-involved reaction.
Hydrogenation of 3-hydroxypropanal into 1,3-propanediol over bimetallic Ru-Ni catalyst
Li, Li-Jun,Yi, Wen-Jun,Liu, Tian-Wei,Huang, Chen,Chao, Zi-Sheng
, p. 32027 - 32037 (2017)
A series of Ni-based catalysts, including Ru/SiO2, Ni/SiO2 and Ru-Ni/SiO2, were prepared and employed in the hydrogenation of 3-hydroxypropanal (3-HPA) to 1,3-propanediol (1,3-PDO). The catalysts were systematically characterized by means of XRD, TEM, HRTEM, SEAD, XPS, H2-TPD, H2-TPR and N2-physisorption. It was indicated that the introduction of Ru onto the Ni/SiO2 not only increased the porosity of catalyst and the degree of dispersion of Ni species but also promoted the reduction of Ni2+ to Ni0 and the generation of active hydrogen species. The catalytic performance evaluation showed that the Ru-40Ni/SiO2 catalyst, among all others, could provide the largest yield of 1,3-PDO (above 99.0%) and highest TOF (4.70 × 103 S-1). The optimized reaction conditions over the Ru-40Ni/SiO2 catalyst had been established as follows: reaction temperature = 80 °C, H2 pressure = 2.0 MPa and LHSV = 0.4 h-1. In consideration of its extremely low H2 pressure and very high yield of 1,3-PDO for the hydrogenation of 3-HPA, to the best of our knowledge, the Ru-40Ni/SiO2 catalyst appeared to be the most efficient catalyst among all others reported in the literature. The good performance enabled the Ru-40Ni/SiO2 catalyst to be very promising in its industrial application.
Nanoparticulate Pt on mesoporous SBA-15 doped with extremely low amount of W as a highly selective catalyst for glycerol hydrogenolysis to 1,3-propanediol
Fan, Yiqiu,Cheng, Shijie,Wang, Hao,Ye, Danhong,Xie, Songhai,Pei, Yan,Hu, Huarong,Hua, Weiming,Li, Zhen Hua,Qiao, Minghua,Zong, Baoning
, p. 2174 - 2183 (2017)
It has been documented that W-modified Pt catalysts with relatively high tungsten contents are effective for the catalytic transformation of biodiesel-derived glycerol to 1,3-propanediol (1,3-PDO). Herein, we report a new finding that Pt/W-SBA-15 catalysts with extremely low W/Si atomic ratios (≤1/80) exhibit excellent catalytic performance in the hydrogenolysis of glycerol to 1,3-PDO. In particular, a Pt/W-SBA-15 catalyst with the W/Si ratio of as low as 1/640 (Pt/W-SBA-15(1/640)) gave rise to the highest 1,3-PDO selectivity of 70.8% at a high glycerol conversion of 86.8% and thus afforded the highest yield of 1,3-PDO of 61.5%. A combination of characterization techniques evidenced that tungsten was homogeneously incorporated into SBA-15 in the form of isolated tetragonal WO4 and only displayed Lewis acidity. The particle size of Pt evolved in a reverse volcanic curve with the W/Si ratio, with the smallest size being observed for Pt/W-SBA-15(1/640). Control experiments indicated strong synergy between Pt nanoparticles (NPs) and WO4 in the hydrogenolysis of glycerol. A probe reaction suggested that Br?nsted acid sites were generated in situ on the Pt/W-SBA-15 catalysts in a H2 atmosphere by the reaction between WO4 and spillover H atoms from the Pt NPs. It is plausible that the hydrided WO4 functioned as a highly selective active centre in the hydrogenolysis of glycerol to 1,3-PDO, whereas the Pt NPs played the role of a reservoir of spillover H atoms. Thus, a good match between the isolated WO4 and the small Pt NPs was responsible for the superior catalytic performance of Pt/W-SBA-15(1/640).
Facilitating Pt?WOx Species Interaction for Efficient Glycerol Hydrogenolysis to 1,3-Propanediol
Zhao, Binbin,Liang, Yu,Liu, Lei,He, Qian,Dong, Jin-Xiang
, p. 3695 - 3705 (2021)
Designing efficient catalysts for glycerol hydrogenolysis to 1,3-propanediol (1,3-PDO), which involves the selective cleavage of the secondary C?O bond, is a challenging task. Current Pt?WOx-based catalysts often provide low atom efficiency of W and Pt toward 1,3-PDO production due to undesired catalyst structures. Herein, we fabricate the highly-dispersed substantially uniform WOx species on inert α-Al2O3 support by simple high-temperature heat-treatment, and the amount of Pt?WOx interface active sites could be adjusted by Pt loading, showing an excellent catalytic performance in glycerol hydrogenolysis at high concentration of glycerol, especially the unprecedented W efficiency (76 g1,3-PDOgW?1 h?1) toward 1,3-PDO. The high catalytic efficiency is attributed to the strong interaction between the isolated WO4 species and platinum, which could in-situ generate the Br?nsted acid sites during the reaction as evidenced by IR analysis with NH3 adsorption.
Understanding the promotional effect of Au on Pt/WO3 in hydrogenolysis of glycerol to 1,3-propanediol
Yang, Chaojun,Zhang, Fan,Lei, Nian,Yang, Man,Liu, Fei,Miao, Zhili,Sun, Yongnan,Zhao, Xiaochen,Wang, Aiqin
, p. 1366 - 1372 (2018)
Pt/Au/WO3 bimetallic catalysts were prepared by impregnation of Pt onto preformed Au/WO3, obtained by a hexadecyl trmethyl ammonium bromide (CTAB)-assisted one-pot synthesis method. The resulting Pt/Au/WO3 catalysts exhibited remarkable synergistic effects for selective hydrogenolysis of glycerol to 1,3-propanediol. The characterization results showed that doping of Au promoted the reduction of both Pt and W at low temperatures and uniform dispersion of Pt on the WO3 support. Furthermore, more low-valence Pt species were produced on the WO3 surface after introduction of Au. These changes in electronic properties resulted in enhancement of both glycerol conversion and selectivity for 1,3-propanediol.
Towards selective electrochemical conversion of glycerol to 1,3-propanediol
James, Olusola O.,Sauter, Waldemar,Schr?der, Uwe
, p. 10818 - 10827 (2018)
1,3-propanediol (1,3-PD) is a bulk chemical with myriad applications in polymers, lubricants, cosmetics, foods industries and in the synthesis of heterocyclic compounds. Current commercial production of 1,3-PD involves a thermocatalytic process using acrolein (DuPont) and ethylene oxide (Shell) as starting feedstock. These feedstocks are petroleum-based and there are many efforts at using glycerol as low cost biomass-derived feedstock for 1,3-PD production. A number of catalyst designs and bacterial & fungal strains are being explored for respective catalytic and fermentation routes to glycerol-to-1,3-PD. However, the electrochemical method received little attention for the purpose. In this work, in order to explore the possibility of using partly refined glycerol byproduct of biodiesel production as feedstock, we investigated conversion and 1,3-PD selectivity of glycerol electrolysis in chloride media. We demonstrated selective glycerol-to-1,3-PD conversion using Pt or RuO2-based dsa as anode and Zn or Pb as cathode in NaCl and KCl at pH 1. This electrochemical glycerol-to-1,3-PD conversion is not only green, it is a potential process network loop between biodiesel production and chlor-alkali industry.
Cu boosting the collaborative effect of Ni and H+in alloyed NiCu/saponite catalysts for hydrogenolysis of glycidol
Cesteros, Yolanda,Gebretsadik, Fiseha Bogale,González, María Dolores,Ruiz-Martinez, Javier,Salagre, Pilar
, p. 9198 - 9207 (2021)
The effect of copper on various acid saponite supported Ni-Cu bimetallic catalysts, prepared with different Ni?:?Cu ratios, was studied for the liquid phase hydrogenolysis of glycidol on a batch reactor at 393 and 453 K. Characterization of the catalysts showed that Ni and Cu are in close contact as the XRD measurements evidenced the formation of an alloy. H2chemisorption results revealed that the measured metallic area progressively decreased with an increase in the wt% of copper. In the presence of high metal activity (higher Ni wt%), the formation of 1,2-propanediol (1,2-PD) outweighed, while acid activity led to the formation of dimerization and oligomerization products. The addition of Cu and the increase of the reaction temperature decreased the diol formation but boosted the 1,3-PD/1,2-PD ratio. This could be explained by an improvement of the collaborative effect between the metal Ni and the H+of the saponite. Therefore, the presence of an appropriate amount of Cu allowed the control of the hydrogenation capacity of Ni and enhanced the collaborative effect of Ni and H+favouring the formation of 1,3-propanediol with respect to 1,2-propanediol.
Selective hydrogenolysis of glycerol to 1,3-propanediol over a Pt/WO 3/TiO2/SiO2 catalyst in aqueous media
Gong, Leifeng,Lu, Yuan,Ding, Yunjie,Lin, Ronghe,Li, Jingwei,Dong, Wenda,Wang, Tao,Chen, Weimiao
, p. 119 - 126 (2010)
SiO2-supported Pt/WO3/TiO2 catalysts were prepared; they were found to be more active and selective than the Pt/WO 3/TiO2 catalyst for glycerol hydrogenolysis to 1,3-propanediol in a slurry batch reactor. The influences of catalyst component, reaction medium, reaction temperature, H2 pressure and reaction time on glycerol hydrogenolysis over the Pt/WO3/TiO2/SiO 2 catalyst were investigated. XRD, TEM, NH3-TPD and Py-IR characterization were employed to reveal the roles of WO3 and TiO2 in the performance of the Pt based-catalysts. XRD patterns and TEM images showed that the presence of TiO2 species in the catalyst favored the dispersion of platinum. The weak Br?nsted acid sites formed by addition of WO3 to the catalyst were concluded to play a key role in selective formation of 1,3-propanediol, based on the results of NH 3-TPD and Py-IR characterization.
Mesoporous Ti-W oxide: Synthesis, characterization, and performance in selective hydrogenolysis of glycerol
Zhang, Yanhua,Zhao, Xiao-Chen,Wang, Yao,Zhou, Likun,Zhang, Junying,Wang, Jia,Wang, Aiqin,Zhang, Tao
, p. 3724 - 3732 (2013)
Mesoporous Ti-W oxides, bearing high surface area, large pore volume, uniform pore size and tunable W/Ti ratios in a wide range (10-40 mol%), were successfully fabricated via an evaporation-induced self-assembly (EISA) strategy. In this approach, the incorporation of W species not only effectively resulted in well-ordered mesoporous structures when calcined below 400 °C but also modified the acidic properties of the obtained oxide composites. The optimal acid amounts (0.47-0.67 mmol g-1 for 400 °C calcinations, 0.25-0.27 mmol g-1 for 500 °C calcinations) were obtained when the W concentration was between 10 and 20 mol%. When calcined at 500 °C, Bronsted acids were generated in Ti90W10-500 and Ti80W20-500. The catalytic performance of these mesoporous solid acids in glycerol hydrogenolysis was studied with a loading of 2 wt% Pt. Pt/Ti100-nWn-500s exhibited high selectivity to 1,3-propanediol (33.5% and 40.3%) and promising catalytic activities (18.4% and 24.2% glycerol conversion) when n is 10 and 20, respectively. This work presents a step forward in the development of highly efficient glycerol hydrogenolysis catalysts and a new understanding of the reaction mechanism of glycerol hydrogenolysis to 1,3-propanediol.
New bulk nickel phosphide catalysts for glycerol hydrogenolysis to 1,2-propanediol
Shi, Guojun,Su, Lijun,Jin, Kai
, p. 180 - 183 (2015)
Transitional metal phosphides were found to have outstanding activity and stability in catalytic hydrotreatments. The bulk trinickel phosphide catalyst with the smallest phosphorus content among the nickel phosphides were synthesized by a hydrothermal method followed by an annealing treatment, and the resulting bulk trinickel phosphide catalysts presented a high purity and morphology of hexagonal prisms. The optimized synthesis conditions include a P:Ni ratio of 3 to 1 and a pH value of 5 in the hydrothermal synthesis stage and a calcination temperature of 773 K in the annealing treatment. The synthesized trinickel phosphides exhibited a low-temperature activity to selective glycerol hydrogenolysis and the high selectivity to 1,2-propanediol.
New approaches to the Pt/WOx/Al2O3 catalytic system behavior for the selective glycerol hydrogenolysis to 1,3-propanediol
García-Fernández,Gandarias,Requies,Güemez,Bennici,Auroux,Arias
, p. 65 - 75 (2015)
Although the hydrogenolysis of glycerol to 1,2-propanediol is already well developed, the production of the more valuable 1,3-propanediol is still a challenge. To achieve this aim, it is essential to design catalysts showing high selectivity toward the CO cleavage of the secondary hydroxyl group in glycerol. In this work, two different series of Pt/WOx/Al2O3 catalytic systems were studied for the selective hydrogenolysis of glycerol to 1,3-propanediol. The results reveal the necessity to control the tungsten surface density in order to obtain highly dispersed polytungstate species, which are able to produce Br?nsted acidity and are involved in the selective formation of 1,3-propanediol. After optimization of the tungsten surface density, the effect of platinum content was also studied. It was found that by improving the interactions between platinum and tungsten oxides, it is possible to increase the selectivity toward 1,3-propanediol. Under optimized conditions, a selectivity toward 1,3-PDO of 51.9% at 53.1% glycerol conversion was obtained. Based on the characterization and activity test results, a reaction mechanism for the Pt-WOx catalytic system in glycerol hydrogenolysis to 1,3-propanediol was also proposed.
Effect of promoters on the selective hydrogenolysis of glycerol over Pt/W-containing catalysts
Wang, Jia,Lei, Nian,Yang, Chaojun,Su, Yang,Zhao, Xiaochen,Wang, Aiqin
, p. 1513 - 1519 (2016)
Diverse promoters, including noble metals (such as Ru, Ir and Rh) and transition metal oxides (such as Re, La, Fe, Zr, Sn and Ce oxides) were introduced into Pt/WOx and Pt/WOx/Al2O3 catalysts to investigate the ability of these promoters to modify activity and selectivity during glycerol hydrogenolysis to 1,3-propanediol. Among these, La exhibited the greatest promotional effect; the introduction of 0.1% La to the Pt/WOx improved activity, selectivity and stability, although the significant increase in selectivity came at the cost of a slight activity loss in the case of the Pt/WOx/Al2O3 catalyst. Transmission electron microscopy, high angle annular dark field scanning tunneling electron microscopy and NH3-temperature programmed desorption all demonstrated that the introduction of La generates a greater quantity of acidic sites on the catalyst surface, and that the majority of the La species are associated with Pt particles. Most of the other additives resulted in only minimal improvements or even detrimental effects with regard to both activity and selectivity, although some appear to improve the stability of the catalyst.
Selective synthesis of 1,3-propanediol from glycidol over a carbon film encapsulated Co catalyst
Sun, Yanyan,Cai, Zhongshun,Li, Xuewen,Chen, Ping,Hou, Zhaoyin
, p. 5022 - 5030 (2019)
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.
Glycerol Hydrogenolysis to 1,3-Propanediol on Tungstate/Zirconia-Supported Platinum: Hydrogen Spillover Facilitated by Pt(1 1 1) Formation
Zhou, Wei,Zhao, Yujun,Wang, Yue,Wang, Shengping,Ma, Xinbin
, p. 3663 - 3671 (2016)
In glycerol hydrogenolysis, WOx and ReOx catalysts have been investigated widely because of their importance for the selectivity of 1,3-propanediol, but few studies have focused on hydrogen spillover. In this work, the hydrogen spillover effect on the catalytic performance was investigated for a series of Pt/WO3/ZrO2 nanocatalysts. The spillover capacities were tuned by changing the tetragonal/monoclinic ZrO2 composition and thermal treatment conditions of the Pt precursor. H2/O2 titration and X-ray photoelectron spectroscopy (XPS) confirm that all of the catalysts present a uniform Pt dispersion and a similar surface electron environment. Diffuse reflectance infrared Fourier transform spectra of adsorbed CO and H2 chemisorption reveal the strong correlation between the amount of Pt(1 1 1) terraces and the spillover capacities. We demonstrate that the reaction rate is influenced by hydrogen spillover, but not the acid amount or acid strength of the catalysts in this case. The important roles of Pt(1 1 1) and WO3 in the spillover process are discussed.
Selective hydrogenolysis of glycerol to 1,3-propanediol over egg-shell type Ir-ReOx catalysts
Luo, Wenting,Lyu, Yuan,Gong, Leifeng,Du, Hong,Wang, Tao,Ding, Yunjie
, p. 13600 - 13608 (2016)
The selective liquid-phase hydrogenolysis of glycerol to 1,3-propanediol over egg-shell catalysts in which the loadings of Ir and Re were both 2 wt% is reported. The shell thickness could be tuned by impregnating a hydrophobic silanized support with an aqueous solution of precursors containing various concentrations of ethanol and using entrapped air to prevent the impregnation solution from entering into the support pellets. The conversion of glycerol for the target reaction over egg-shell catalysts was higher than that over a uniform catalyst and was accompanied by a high selectivity for 1,3-propanediol over 1,2-propanediol. Reacting over the catalyst for which the impregnation solution ethanol concentration was 20 vol% resulted in the highest glycerol conversion (60.9%) and the highest yield of secondary hydroxyl group removal (30.2%). The properties of the egg-shell and uniform catalysts were characterized by XRD, TEM, XPS, H2-TPR, H2-pulse chemisorption and NH3-TPD. An appropriate diffusion distance of the reactants for egg-shell catalysts might result in better catalytic performance because of the high viscosity of the glycerol aqueous solution.
Influence of catalyst pretreatment on catalytic properties and performances of Ru-Re/SiO2 in glycerol hydrogenolysis to propanediols
Ma, Lan,He, Dehua
, p. 148 - 156 (2010)
Bimetallic Ru-Re/SiO2 and monometallic Ru/SiO2 catalysts were prepared by impregnation method and their catalytic performances were evaluated in the hydrogenolysis of glycerol to propanediols (1,2-propanediol and 1,3-propanediol) with a batch type reactor (autoclave) under the reaction conditions of 160 °C, 8.0 MPa and 8 h. Ru-Re/SiO2 showed much higher activity in the hydrogenolysis of glycerol than Ru/SiO2, and the pretreatment conditions of the catalyst precursors had great influence on the catalytic performance of both Ru-Re/SiO2 and Ru/SiO2 catalysts. The physicochemical properties of Ru-Re/SiO2 and Ru/SiO2, such as specific surface areas, crystal phases, morphologies/microstructures, surface element states, reduction behaviors and dispersion of Ru metal, were characterized by N2 adsorption/desorption, XRD, Raman, TEM-EDX, XPS, H2-TPR and CO chemisorption. The results of XRD, TEM-EDX and CO chemisorption characterizations showed that Re component had an effect on promoting the dispersion of Ru species on the surface of SiO2, and the measurements of H2-TPR revealed that the co-existence of Re and Ru components on SiO2 changed the respective reduction behavior of Re or Ru alone. High pre-reduction temperatures would decrease the activities of Ru-Re/SiO2 and Ru/SiO2 catalysts, compared with the corresponding calcined catalysts (without pre-reduction), which actually went through an in-situ reduction during the reaction. XPS analysis indicated that Ru species was in Ru0 metal state, while Re species was mostly in Re oxide state in the spent Ru-Re/SiO2 sample. Re component was probably in rhenium oxide state rather than Re0 metal state to take part in the reaction via interaction with Ru0 metal.
Glycerol hydrogenolysis to n-propanol over Zr-Al composite oxide-supported Pt catalysts
Li, Chuang,He, Bo,Ling, Yu,Tsang, Chi-Wing,Liang, Changhai
, p. 1121 - 1128 (2018)
Zr-Al mixed oxide supported Pt catalysts with different Zr/Al mole ratios (2.5%Pt/ZrxAl1–xOy) were synthesized by an impregnation method and used for the selective hydrogenolysis of glycerol to n-propanol in an autoclave reactor. The catalysts were fully characterized by X-ray powder diffraction, Brunauer-Emmett-Teller surface area analysis, CO chemisorption, H2 temperature- programmed reduction, pyridine-infrared spectroscopy, and NH3-temperature-programmed desorption. The results revealed that the Zr/Al ratio on the support significantly affected the size of the platinum particles and the properties of the acid sites on the catalysts. The catalytic performance was well correlated with the acidic properties of the catalyst; specifically, more acid sites contributed to the conversion and strong acid sites with a specific intensity contributed to the deep dehydration of glycerol to form n-propanol. Among the tested catalysts, 2.5 wt% Pt/Zr0.7Al0.3Oy exhibited excellent selectivity for n-propanol with 81.2% glycerol conversion at 240 °C and 6.0 MPa H2 pressure when 10% aqueous glycerol solution was used as the substrate. In addition, the effect of various reaction parameters, such as H2 content, reaction temperature, reaction time, and number of experimental cycles were studied to determine the optimized reaction conditions and to evaluate the stability of the catalyst.
Small Current but Highly Productive Synthesis of 1,3-Propanediol from Glycerol by an Electrode-Driven Metabolic Shift in Klebsiella pneumoniae L17
Kim, Changman,Lee, Jae Hyeon,Baek, Jiyun,Kong, Da Seul,Na, Jeong-Geol,Lee, Jinwon,Sundstrom, Eric,Park, Sunghoon,Kim, Jung Rae
, p. 564 - 573 (2020)
Electrofermentation actively regulates the bacterial redox state, which is essential for bioconversion and has been highlighted as an effective method for further improvements of the productivity of either reduced or oxidized platform chemicals. 1,3-Propanediol (1,3-PDO) is an industrial value-added chemical that can be produced from glycerol fermentation. The bioconversion of 1,3-PDO from glycerol requires additional reducing energy under anoxic conditions. The cathode-based conversion of glycerol to 1,3-PDO with various electron shuttles (2-hydroxy-1,4-naphthoquinone, neutral red, and hydroquinone) using Klebsiella pneumoniae L17 was investigated. The externally poised potential of ?0.9 V vs. Ag/AgCl to the cathode increased 1,3-PDO (35.5±3.1 mm) production if 100 μm neutral red was used compared with non-bioelectrochemical system fermentation (23.7±2.4 mm). Stoichiometric metabolic flux and transcriptional analysis indicated a shift in the carbon flux toward the glycerol reductive pathway. The homologous overexpression of glycerol dehydratase (DhaB) and 1,3-PDO oxidoreductase (DhaT) enzymes synergistically enhanced 1,3-PDO conversion (39.3±0.8 mm) under cathode-driven fermentation. Interestingly, a small current uptake (0.23 mmol of electrons) caused significant metabolic flux changes with a concomitant increase in 1,3-PDO production. This suggests that both an increase in 1,3-PDO production and regulation of the cellular metabolic pathway are feasible by electrode-driven control in cathodic electrofermentation.
Hydrogenolysis of Glycerol to 1,3-propanediol under Low Hydrogen Pressure over WOx-Supported Single/Pseudo-Single Atom Pt Catalyst
Wang, Jia,Zhao, Xiaochen,Lei, Nian,Li, Lin,Zhang, Leilei,Xu, Shutao,Miao, Shu,Pan, Xiaoli,Wang, Aiqin,Zhang, Tao
, p. 784 - 790 (2016)
Single/pseudo-single atom Pt catalyst was prepared on mesoporous WOx. The large surface area and abundant oxygen vacancies of WOx improve the Pt dispersion and stabilize the Pt isolation. This newly prepared catalyst exhibited outstanding hydrogenolysis activity under 1 MPa H2 pressure with a very high space-time yield towards 1,3-propanediol (3.78 g gPt-1 h-1) in Pt-W catalysts. The highly isolated Pt structure is thought to contribute to the excellent H2 dissociation capacity over Pt/WOx. The high selectivity towards 1,3-propanediol is attributed to the heterolytic dissociation of H2 at the interface of Pt and WOx (providing specific Br?nsted acid sites and the concerted dehydration-hydrogenation reaction) and the bond formation between glycerol and WOx, which favors/stabilizes the formation of a secondary carbocation intermediate as well as triggers the redox cycle of the W species (W6+?W5+).
Aqueous-phase hydrogenolysis of glycerol to 1,3-propanediol over Pt-H 4SiW12O40/SiO2
Zhu, Shanhui,Zhu, Yulei,Hao, Shunli,Chen, Lungang,Zhang, Bin,Li, Yongwang
, p. 267 - 274 (2012)
Hydrogenolysis of glycerol to 1,3-propanediol in aqueous-phase was investigated over Pt-H4SiW12O40/SiO2 bi-functional catalysts with different H4SiW12O 40 (HSiW) loading. Among them, Pt-15HSiW/SiO2 showed superior performance due to the good dispersion of Pt and appropriate acidity. It is found that Bronsted acid sites facilitate to produce 1,3-PDO selectively confirmed by Py-IR. The effects of weight hourly space velocity, reaction temperature and hydrogen pressure were also examined. The optimized Pt-HSiW/SiO2 catalyst showed a 31.4% yield of 1,3-propanediol with glycerol conversion of 81.2% at 200 °C and 6 MPa. Graphical Abstract: [Figure not available: see fulltext.].
Effect of promoters on hydrogenation of diethyl malonate to 1,3-propanediol over nano copper-based catalysts
Ding, Tongmei,Tian, Hengshui,Liu, Jichang,Wu, Wenbin,Zhao, Bingqin
, p. 10 - 15 (2016)
Copper-based catalysts were prepared via ammonia evaporation co-precipitation method. Structure evolutions of the catalysts were systematically characterized by XRD, FTIR, TG, SEM, N2-physisorption, ICP-AES, N2O chemisorption and XPS focusing on the influence of promoters on the catalytic behavior in the hydrogenation of diethyl malonate to 1,3-propanediol. The results showed that diethyl malonate conversion and 1,3-propanediol selectivity could reach 96.71% and 29.76% respectively at 473 K with 2.0 MPa and 1.8 h- 1 with boron as promoter. The improved catalytic performance of Cu-B/SiO2 catalyst could be attributed to more Cu0 formed with the inhibition of copper phyllosilicate and better dispersion of copper species.
Method and system for producing 1, 3-propylene glycol by multi-step method
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Paragraph 0101; 0108-0110; 0117-0119; 0126-0128; 0135-0141, (2021/01/28)
The invention discloses a method and a system for producing 1, 3-propylene glycol by a multi-step method. The method comprises the following steps: carrying out dehydration reaction on 1, 3-dichloropropanol and a dehydration catalyst to prepare 1, 3-dichloropropene; carrying out a first hydrolysis reaction on a first mixed reaction system containing the 1, 3-dichloropropene, a first hydrolysis agent and a first solvent to prepare 3-chloro-2-propene-1-alcohol; carrying out hydrogenation reaction on the 3-chloro-2-propene-1-alcohol and a hydrogenation catalyst to prepare 3-chloropropanol; and carrying out a second hydrolysis reaction on a second mixed reaction system containing the 3-chloropropanol, a second hydrolysis agent and a second solvent to prepare the 1, 3-propylene glycol. According to the method, 1, 3-dichloropropanol is used as a raw material, the important chemical raw material 1, 3-propylene glycol is prepared through a dehydration, hydrolysis, hydrogenation and hydrolysisfour-step method, and the method has the advantages of mild reaction conditions, low cost, environmental protection, economy and the like.
