Deactivation mechanism and regeneration of carbon nanocomposite catalyst for acetylene hydrochlorination

Li, Xingyun; Li, Pan; Pan, Xiulian; Ma, Heng; Bao, Xinhe

doi:10.1016/j.apcatb.2017.03.046

Cited by 73 publications

(44 citation statements)

References 29 publications

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“…Still, carbon materials, including defect‐rich carbons, graphitic carbon nitride, and heteroatom‐doped carbons ( i. e ., N, P, B, S) are highly desirable alternatives, owing to their significant environmental and cost advantages compared to metal‐based catalysts . In particular, nitrogen‐doped carbons (NCs), derived via carbonization of C/N‐precursors ( i. e ., polyaniline, polydopamine, ZIF‐8), stand out as the most promising candidates, rivaling the initial activity of their metal‐based analogues at elevated reaction temperatures . Despite these encouraging results, the applicability of NCs is hindered by their insufficient durability under relevant process conditions ( T =403‐453 K, P =1.5 bar, HCl : C 2 H 2 =1.1 : 1) .…”

Section: Figurementioning

confidence: 99%

“…Despite these encouraging results, the applicability of NCs is hindered by their insufficient durability under relevant process conditions ( T =403‐453 K, P =1.5 bar, HCl : C 2 H 2 =1.1 : 1) . In particular, pore blockage through the formation of carbonaceous residues has been identified as the major reason for catalyst deactivation . A possible strategy to mitigate the impact of coke species is to enhance the micropore volume and introduce auxiliary pores to improve the accessibility of the active sites within the micropores and facilitate the molecular diffusion of reactants, intermediates, and products.…”

Section: Figurementioning

confidence: 99%

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Nitrogen‐Doped Carbons with Hierarchical Porosity via Chemical Blowing Towards Long‐Lived Metal‐Free Catalysts for Acetylene Hydrochlorination

et al. 2020

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Porous nitrogen‐doped carbons (NCs) are sustainable alternatives to the toxic mercury‐based acetylene hydrochlorination catalysts applied in the manufacture of polyvinyl chloride. However, the application of NCs as metal‐free catalysts is hampered by their insufficient durability under industrially relevant process conditions. In particular, pore blockage leads to accelerated deactivation of NCs compared to the state‐of‐the‐art precious metal‐based systems. Herein, we develop a salt template‐assisted synthesis strategy coupled with chemical blowing to tune the textural properties of NCs, while preserving the N‐content and speciation. The addition of metal salts (i. e., Mg(OAc)2 or CaCO3) enhances gas evolution, leading to an increased formation of micro‐ and mesopores, while the in‐situ generated CaO/CaCl2 and MgO/MgCl2 develop auxiliary pore networks. Micropores are easily blocked during acetylene hydrochlorination, but meso‐ and macropores are structurally stable, enhancing the lifetime of hierarchical NCs by ca. 50 times compared to their non‐templated analogues, rivaling the stability of benchmark metal‐based catalysts.

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Section: Figurementioning

confidence: 99%

Section: Figurementioning

confidence: 99%

Nitrogen‐Doped Carbons with Hierarchical Porosity via Chemical Blowing Towards Long‐Lived Metal‐Free Catalysts for Acetylene Hydrochlorination

et al. 2020

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“…Hydrochlorination of acetylene to produce vinyl chloride monomer (VCM) is an important industrial route, especially in coal‐rich but oil‐deficient countries such as China and India . VCM is mainly synthesized polyvinyl chloride (PVC), which is world's third largest engineering material.…”

Section: Introductionmentioning

confidence: 99%

The Effect of N‐Doping in Activated Carbon‐Supported Au‐Sr Catalysts for Acetylene Hydrochlorination to Vinyl Chloride

Zhang

et al. 2018

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We used N-doped activated carbon (NAC) as support to prepare a novel AuÀSr catalyst and evaluated the effect of Ndopants on the performance of AuÀSr catalyst in acetylene hydrochlorination. A promoting effect was observed when N atoms were incorporated into AC framework, and the prepared SrAu/NAC catalyst demonstrated optimal activity compared with the undoped Au/AC and SrAu/AC catalysts. The SrAu/NAC also showed an excellent stability during the 500 h test, with acetylene conversion and vinyl chloride selectivity both exceeding 99.9%. A detailed characterization was investigated through XPS, TPD, TPR, TGA, PXRD, TEM, AAS, and BET to reveal the physicochemical properties of the related catalysts. It is demonstrated that the NAC can function as an effective support to enhance activity and life of Au-based catalysts with unique electronic property, and the presence of doped nitrogen species as anchor sites is beneficial to increasing the electron density of active Au(III) center through electron transfer from doped N atoms to the active Au(III) species, and stabilizing active Au(III) ions and retarding its reduction within catalyst preparation and use process. Moreover, the combination of N-dopants and strontium additive may promote a synergistic effect to make active Au species disperse better and significantly enhance the adsorption of HCl, remarkably suppress the reduction of active cationic Au(III), and effectively inhibit carbon deposition in the catalytic reaction.

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“…Au 3+ and Sn(II) is stronger, whereas Sn(II) can effectively stabilize Au 3+ . As shown in Figure , the characteristic reduction peaks of Cu 2+ in CuCl 2 /AC is appeared at approximately 352.7 °C, while the same peaks is observed at 525.6 °C in case of Cu–MOF/AC, demonstrating the interaction between Cu 2+ and o‐phthalic acid. The obvious reduction peak of Sn 2+ is observed at ca.487.5 °C .…”

Section: Resultsmentioning

confidence: 94%

“…Table illustrates that the specific surface area and total pore volume of catalysts decrease after the reaction, which is related to the deposition of carbon on catalysts . However, the coke deposition is due to the polymerization of acetylene and vinyl chloride during the hydrochlorination of acetylene . Figure displays the TG curve for Sn‐MOF and Cu–MOF recorded between 25 and 800 °C under nitrogen atmosphere.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of X–MOF/AC (X=tin or copper) Catalysts for the Acetylene Hydrochlorination

et al. 2019

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In this study, metal organic framework/activated carbon catalysts (X–MOF/AC, where X=Sn or Cu) were synthesized using a facile method and used for the acetylene hydrochlorination reaction. The prepared catalysts were characterized using Fouriertransform infrared spectroscopy (FTIR), X‐ray diffraction analysis(XRD), nitrogen adsorption‐desorption analysis, thermo‐gravimetric analysis (TGA), acetylene temperature‐programmed desorption experiments (C2H2‐TPD), hydrogen temperature‐programmed reduction experiments (H2‐TPR), X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy‐energy dispersive spectroscopy (SEM‐EDS). Compared with Cu–MOF/AC, Sn‐MOF/AC behaved the highest acetylene conversion of 93.5% under the conditions of 200 °C and an acetylene gas space velocity of 30 h−1. Furthermore, XRD, TGA and SEM‐EDS results showed that Sn‐MOF and Cu–MOF possesse different morphology and thermalstability, respectively. Additionally, C2H2‐TPD and TGA results indicated that Sn‐MOF/AC displays the higher acetylene adsorption and the better anti‐coking ability as compare to Cu–MOF/AC.

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Deactivation mechanism and regeneration of carbon nanocomposite catalyst for acetylene hydrochlorination

Cited by 73 publications

References 29 publications

Nitrogen‐Doped Carbons with Hierarchical Porosity via Chemical Blowing Towards Long‐Lived Metal‐Free Catalysts for Acetylene Hydrochlorination

Nitrogen‐Doped Carbons with Hierarchical Porosity via Chemical Blowing Towards Long‐Lived Metal‐Free Catalysts for Acetylene Hydrochlorination

The Effect of N‐Doping in Activated Carbon‐Supported Au‐Sr Catalysts for Acetylene Hydrochlorination to Vinyl Chloride

Synthesis and Characterization of X–MOF/AC (X=tin or copper) Catalysts for the Acetylene Hydrochlorination

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