Effect of Mo-modification over Phillips CrOx/SiO2 catalyst for ethylene polymerization

Ma, Yue; Cheng, Ruihua; Li, Jiajun; Zhong, Lei; Liu, Zhen; He, Xuelian; Liu, Boping

doi:10.1016/j.jorganchem.2015.05.058

Cited by 4 publications

(3 citation statements)

References 40 publications

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“…Obviously, the reduction peak of CrMn-HS shifted to a higher temperature due to the presence of sulfate, indicating that the reduction ability of the spent adsorbent weakens greatly at low temperature, which also confirmed the previous XRD and SEM-EDS results. The reduction processes could correspond to the reducing behaviors of Cr 2 (SO 4 ) 3 , and MnSO 4 as follows: …”

Section: Resultsmentioning

confidence: 99%

Cr Doping MnO_x Adsorbent Significantly Improving Hg⁰ Removal and SO₂ Resistance from Coal-Fired Flue Gas and the Mechanism Investigation

Zhang

Hou

Chen

et al. 2018

Ind. Eng. Chem. Res.

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A series of binary Mn-based materials (Fe-MnO x , Cu-MnO x , Cr-MnO x , and Mo-MnO x ) were prepared by the coprecipitation method, and the mechanism for elemental mercury (Hg 0 ) removal of Cr-MnO x in the absence and presence of SO 2 was investigated. The physicochemical structure properties of the fresh as well as spent Cr-MnO x samples were well characterized by the methods of N 2 physisorption, XRD, SEM-EDS, FTIR, H 2 -TPR, XPS, and TPD. The experiment results revealed that the loading of Cr into/onto MnO x yielded above 90% of Hg 0 removal efficiency in the presence of SO 2 at 120 °C. However, the appearance of SO 2 would lead to the formation of chromium sulfate/sulfite and manganese sulfate/sulfite although much superior SO 2 resistance was obtained. According to the N 2 physisorption and XRD characterization results, Cr doping can enlarge the BET surface area of MnO x when Cr was doped into/ onto MnO 2 , and the MnCrO 4 mixed oxide material was produced. Moreover, the H 2 -TPR result exhibited that Cr loading into/onto MnO x enhanced the redox property of Cr-MnO x mixed oxides and many more easily reduced species appeared in the mixture. The larger surface area and an abundance of reactive species could benefit from excellent performances of Hg 0 removal and superior SO 2 resistance although the DFT calculation showed almost the same adsorption energies of Hg 0 on MnO 2 (110) and Cr-MnO 2 (110) surfaces. The DFT calculation exhibited that the adsorption energy of SO 2 on the surface of Cr-MnO 2 (110) was much lower than that on MnO 2 (110), implying that Cr doping into MnO 2 would decrease the adsorption behavior of SO 2 , thereby improving its SO 2 resistance performance.

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Section: Resultsmentioning

confidence: 99%

Cr Doping MnO_x Adsorbent Significantly Improving Hg⁰ Removal and SO₂ Resistance from Coal-Fired Flue Gas and the Mechanism Investigation

Zhang

Hou

Chen

et al. 2018

Ind. Eng. Chem. Res.

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“…TREF as a physical separating method on the basis of crystallinity of polymer sample has been widespread applied in polymer fractionation and characterization . Also, SSA as an effective means which contains a series of self‐nucleation and annealing steps has been used for analyzing and charactering the polymer fractionations . SCBD of the copolymers obtained from (Cr–V) 600 , (Cr–V–F) 600 , and (Cr–V–F) 500 designated as PE‐1, PE‐2, and PE‐3 were measured using TREF and SSA.…”

Section: Resultsmentioning

confidence: 99%

“…The ethylene/1‐hexene copolymers were fractionated by a self‐made TREF system . The equipment included an 850 mL column type fractionation bottle (height: 156 mm; diameter: 84 mm) filled with quartz sand, a silicone oil bath with thermostat (Huber, POLYTSTAT CC2‐225B ± 0.02 °C), a pump (KNF Lab, STEPDOS 08 S), a rotary evaporator (EYELA) and a nitrogen gas container.…”

Section: Methodsmentioning

confidence: 99%

A Novel SiO₂‐Supported Fluorine Modified Chromium–Vanadium Bimetallic Catalyst for Ethylene Polymerization and Ethylene/1‐Hexene Copolymerization

Sun

Wang

Cheng

et al. 2017

Macro Reaction Engineering

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Phillips catalyst is one of the most significant industrial ethylene polymerization catalysts. Chemical modifications have been carried out to tune the Phillips catalyst performance and improve the polyethylene properties. After the modification of the catalyst by fluorine, the polyethylene product with higher molecular weight (MW) and narrower molecular weight distribution (MWD) is suitable for producing automobile fuel tanks. Vanadium containing Phillips catalyst enhances α‐olefin incorporation and MW regulation. In present work, fluorine modified and unmodified chromium–vanadium (Cr–V) bimetallic catalysts are prepared and explored. Compared with the fluorine‐free catalyst, the activities of F‐modified bimetallic catalysts slightly decrease with the increasing MW of the product and the hydrogen response increases slightly. Due to the synergistic effect of the chromium, vanadium and fluorine on the silica gel support, the short‐chain branch distribution (SCBD) of copolymers from F‐modified Cr–V bimetallic catalyst (Cr–V–F)600 is more beneficial than that of Cr–V bimetallic catalyst (Cr–V)600 and F‐modified Cr–V bimetallic catalyst (Cr–V–F)500. The fluorination of Cr–V bimetallic catalysts has not only preserved the high polyethylene activity of bimetallic active sites but also produced the advantage of the high MW ability from fluorine.

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Modification of the (SiO2/MgO/MgCl2)·TiCl x Ziegler-Natta polyethylene catalysts using the third metal elements

Cheng

et al. 2017

Chin J Polym Sci

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Effect of Mo-modification over Phillips CrOx/SiO2 catalyst for ethylene polymerization

Cited by 4 publications

References 40 publications

Cr Doping MnO_x Adsorbent Significantly Improving Hg⁰ Removal and SO₂ Resistance from Coal-Fired Flue Gas and the Mechanism Investigation

Cr Doping MnO_x Adsorbent Significantly Improving Hg⁰ Removal and SO₂ Resistance from Coal-Fired Flue Gas and the Mechanism Investigation

A Novel SiO₂‐Supported Fluorine Modified Chromium–Vanadium Bimetallic Catalyst for Ethylene Polymerization and Ethylene/1‐Hexene Copolymerization

Modification of the (SiO2/MgO/MgCl2)·TiCl x Ziegler-Natta polyethylene catalysts using the third metal elements

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Effect of Mo-modification over Phillips CrOx/SiO2 catalyst for ethylene polymerization

Cited by 4 publications

References 40 publications

Cr Doping MnOx Adsorbent Significantly Improving Hg0 Removal and SO2 Resistance from Coal-Fired Flue Gas and the Mechanism Investigation

Cr Doping MnOx Adsorbent Significantly Improving Hg0 Removal and SO2 Resistance from Coal-Fired Flue Gas and the Mechanism Investigation

A Novel SiO2‐Supported Fluorine Modified Chromium–Vanadium Bimetallic Catalyst for Ethylene Polymerization and Ethylene/1‐Hexene Copolymerization

Modification of the (SiO2/MgO/MgCl2)·TiCl x Ziegler-Natta polyethylene catalysts using the third metal elements

Contact Info

Product

Resources

About

Cr Doping MnO_x Adsorbent Significantly Improving Hg⁰ Removal and SO₂ Resistance from Coal-Fired Flue Gas and the Mechanism Investigation

Cr Doping MnO_x Adsorbent Significantly Improving Hg⁰ Removal and SO₂ Resistance from Coal-Fired Flue Gas and the Mechanism Investigation

A Novel SiO₂‐Supported Fluorine Modified Chromium–Vanadium Bimetallic Catalyst for Ethylene Polymerization and Ethylene/1‐Hexene Copolymerization