Alumina incorporated with mesoporous carbon as a novel support of Pt catalyst for asymmetric hydrogenation

Li, Qiang; Zhang, Xueqin; Xiao, Mingqing; Liu, Yongjun

doi:10.1016/j.catcom.2013.07.044

Cited by 19 publications

(4 citation statements)

References 26 publications

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“…Li et al prepared Pt catalysts supported on composite materials consisting of carbon incorporated with different alumina contents by a chelate-assisted coassembly method. Carbon incorporated with 10–15 wt % alumina was favorable for achieving high Pt dispersion and retained the mesostructure of carbon.…”

Section: Hydrogenation Of Co Bondsmentioning

confidence: 99%

Recent Progress in Heterogeneous Asymmetric Hydrogenation of C═O and C═C Bonds on Supported Noble Metal Catalysts

2017

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The ease of separation, simple regeneration, and the usually high stability of solid catalysts facilitating continuous production processes have stimulated the development of heterogeneous asymmetric hydrogenation catalysis. The simplest and so far most promising strategy to induce enantioselectivity to solid metal catalysts is their modification by chiral organic compounds, as most prominently represented by the cinchona-modified Pt and Pd catalysts for the asymmetric hydrogenation of activated C═O and C═C bonds. In this Review, we provide a systematic account of the research accomplished in the past decade on noble metal-based heterogeneous asymmetric hydrogenation of prochiral C═O and C═C bonds, including all important facets of these catalytic systems. The advances made are critically analyzed, and future research challenges are identified.

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Section: Hydrogenation Of Co Bondsmentioning

confidence: 99%

Recent Progress in Heterogeneous Asymmetric Hydrogenation of C═O and C═C Bonds on Supported Noble Metal Catalysts

2017

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“…As shown in Figure , the Al–C support exhibited a classic IV type curve with an H2 hysteresis loop ranging from 0.4 to 0.75, corresponding to a typical mesoporous structure, and the mesopore size was concentrated at around 4.7 nm. Well-developed and uniformly dispersed mesopores were formed by the removal of the F127 template and burnout of C, H, and O atoms from the phenolic resin framework during the pyrolysis process. , The adsorption isotherms of the Zr/Al–C catalysts also displayed a classic IV type curve with an apparent H2 hysteresis loop and exhibited a narrow pore size distribution …”

Section: Resultsmentioning

confidence: 99%

“…V meso d (cm 3 g −1 ) V total (cm process. 38,39 The adsorption isotherms of the Zr/Al−C catalysts also displayed a classic IV type curve with an apparent H2 hysteresis loop and exhibited a narrow pore size distribution. 40 The textural properties of the samples are summarized in Table 1.…”

Section: Structural Characterization Of the Zr−al−c Catalystmentioning

confidence: 99%

Zirconia Nanoparticles Uniformly Supported on Mesoporous Alumina–Carbon as a Highly Efficient Catalyst for the Direct Ethanol-to-Butadiene Reaction

Hao,

Zhou,

Gao

et al. 2024

ACS Sustainable Chem. Eng.

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The direct ethanol-to-butadiene (ETB) reaction is a complex tandem reaction, and the precise control of multifunctional active sites is the key to improving the production of butadiene. Considering the fact that the synergistic effect of Zr−Al dual active centers and the hydrophobicity of the carbon surface are beneficial for the direct ETB reaction, a multifunctional Zr/Al−C catalyst has been prepared via the initial wet impregnation using zirconium nitrate as the precursor and mesoporous alumina− carbon as the support. The obtained zirconia nanoparticles are uniformly dispersed on mesoporous alumina−carbon with a mean particle size of about 3.5 nm due to the confinement of the mesoporous channels and the strong interaction between alumina and zirconia. The 10Zr/Al−C catalyst with a zirconia loading of about 10 wt % exhibits much higher butadiene selectivity (58 vs 6.2%) and ethanol conversion (95 vs 70%) compared with mesoporous Al−C at 375 °C under a space velocity of 4.74 h −1 , due to the formation of a zirconia−alumina solid solution. Moreover, the increase of Zr loading led to the increased medium strong acid active sites and the decreased strong acid active sites due to various oxygen vacancies, which affected the butadiene selectivity. It was found that an appropriate strong acid/medium strong acid ratio of about 0.43 and a strong base/total base ratio of about 0.17 were beneficial for the balance of each tandem step, which was necessary to achieve high butadiene selectivity. The recycling studies showed that the 10Zr/Al−C catalyst could maintain a high ethanol conversion of 89% and a butadiene selectivity of 50% after running for 120 h. The multifunctional Zr/Al−C catalyst provides an efficient method for the direct ethanol-to-butadiene reaction.

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“…Several methods can be used for managing the surface properties of calumina, for example playing with the temperature of calcination [28], the digestion of the aluminum hydroxide precursor [29], or the incorporation of a template [22,30]. The acidity of c-alumina is a very crucial parameter that plays an effective role in many catalytic reactions as isomerization [31], hydrocracking [32], hydrogenation-dehydrogenation reactions [33], and dehydration [12]. For Si/Al catalysts obtained by calcination of SBA-15 and Al-SBA-15 (prepared with different Si/Al ratios), the activity of the catalysts for cumene conversion was perfectly correlated with the total acidity of the material [34].…”

Section: Introductionmentioning

confidence: 99%

A new route for the synthesis of self-acidified and granulated mesoporous alumina catalyst with superior Lewis acidity and its application in cumene conversion

et al. 2019

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Self-acidified and granulated mesoporous alumina (SAGMA) with dendritic-like microscopic shape was prepared by a new route that involves: (a) direct dehydration of AlCl 3 (in the presence of capping petroleum wax), and (b) oxi-dation of intermediary AlCl 3 -nanorods. The AlCl 3 solution dispersed in petro-leum wax (capping media) was firstly dehydrated at 100 °C under inert atmosphere for manufacturing anhydrous AlCl 3 -nanorods (length: 50-100 nm; diameter: 5-10 nm). In a second step, this support was oxidized into c-alumina at 300 °C, under air atmosphere. In the course of the manufacturing process, released chlorine was deposited at the surface of the nanorods (more specifically during the oxidation step). The binding of chlorine (5.35%, w/w at the surface) onto c-alumina was demonstrated by both electron dispersive X-ray analysis (SEM-EDX) and Fourier-transformed infrared spectroscopy. Specific surface area reached 230 m 2 g -1 ; the average pore size was 7.8 nm. Material charac-terization was completed by measuring the surface acidity through both tem-perature-programmed desorption and pyridine desorption. The morphology and the phase structure were investigated using scanning electron microscopy and X-ray diffraction analysis, respectively. SAGMA (c-alumina) can be described as a strong Lewis (1.713 mmol g -1 ; i.e., about 93% of total acid sites) and Brønsted acid catalyst supported on a mesoporous structure (self-granular size of 177-250 lm). Cumene conversion (through a dealkylation pathway) was tested on SAGMA: maximum catalytic activity reached 87% at 300 °C. The conversion is highly selective: the reaction produces benzene and only traces of ethylbenzene (mass fraction below 4% compared to benzene). Apart from this good catalytic efficiency, the material is characterized by its strong stability in terms of both catalytic activity (loss less than 2%, for optimum conditions) and surface acidity (loss less than 3%), even for long reaction times (i.e., 24 h) under severe conditions (i.e., T 300 °C). This new material, easily manufactured, is characterized by high efficiency and selectivity in cumene conversion into benzene, associated with high acidity and good stability

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Alumina incorporated with mesoporous carbon as a novel support of Pt catalyst for asymmetric hydrogenation

Cited by 19 publications

References 26 publications

Recent Progress in Heterogeneous Asymmetric Hydrogenation of C═O and C═C Bonds on Supported Noble Metal Catalysts

Recent Progress in Heterogeneous Asymmetric Hydrogenation of C═O and C═C Bonds on Supported Noble Metal Catalysts

Zirconia Nanoparticles Uniformly Supported on Mesoporous Alumina–Carbon as a Highly Efficient Catalyst for the Direct Ethanol-to-Butadiene Reaction

A new route for the synthesis of self-acidified and granulated mesoporous alumina catalyst with superior Lewis acidity and its application in cumene conversion

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