Nature of Active Nickel Sites and Initiation Mechanism for Ethylene Oligomerization on Heterogeneous Ni-beta Catalysts

Moussa, Sara; Concepción, Patricia; Arribas, María Adoración Merino; Martı́nez, Agustı́n

doi:10.1021/acscatal.7b03970

Cited by 112 publications

(134 citation statements)

References 63 publications

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“…Oligomerization reaction of ethylene has been studied on various heterogeneous catalysts such as, metal oxides and sulfates, micro and mesoporous aluminosilicates,, and metal organic frameworks (MOFs) . Compared to other solid catalysts for ethylene oligomerization reaction, nickel (Ni 2+ ) containing microporous materials (such as zeolites and MOFs) offer the opportunity to control and optimize reaction rate and selectivity of these reactions . ETS‐10 (Engelhard Titanosilicate‐10) is a thermally stable microporous crystalline titanosilicate (Si/Ti=5) containing [TiO 6 ] units, which generate a −2 charge (due to Ti 4+ ),, capable of loading significant amounts of divalent cations for ion exchange and water treatment applications ,.…”

Section: Figurementioning

confidence: 99%

Ethylene Oligomerization to Select Oligomers on Ni‐ETS‐10

2018

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The oligomerization of short alkenes (ethylene and propylene) can be used for producing commodity chemicals. Various catalysts have been used for alkene oligomerization, among which ordered microporous catalysts are thermally and mechanically stable and are already established for large-scale industrial applications. In this work, we demonstrate ethylene oligomerization reaction on a microporous titanosilicate ETS-10 (Engelhard Titanosiliate-10) exchanged with Ni 2 + (Ni-ETS-10). We demonstrate a template-free and fluoride-free ETS-10 synthesis method that does not produce impurities commonly seen in hydrothermal ETS-10 synthesis. Ni-ETS-10 showed high C 2 conversion rate, high selectivity to C 4 and high stability comparing to other microporous catalysts investigated in this work for ethylene oligomerization reaction.Oligomerization reaction of ethylene has been studied on various heterogeneous catalysts such as, metal oxides and sulfates, [1][2][3][4][5] micro and mesoporous aluminosilicates, [1,[6][7][8][9][10][11][12][13][14][15][16][17] and metal organic frameworks (MOFs). [18][19][20][21][22][23] Compared to other solid catalysts for ethylene oligomerization reaction, nickel (Ni 2 + ) containing microporous materials (such as zeolites and MOFs) offer the opportunity to control and optimize reaction rate and selectivity of these reactions. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] ETS-10 (Engelhard Titanosilicate-10) is a thermally stable microporous crystalline titanosilicate (Si/Ti = 5) containing [TiO 6 ] units, which generate a À2 charge (due to Ti 4 + ), [24,25] capable of loading significant amounts of divalent cations for ion exchange and water treatment applications. [26,27] Since ETS-10 is capable of loading a broad spectrum of divalent transition metal cations, [26,27] this versatile ion-exchange capability of ETS-10 was therefore exploited in this study, and Ni 2 + was exchanged into the framework for ethylene oligomerization. The framework structure of ETS-10 consists of periodic large 12-member ring pores (7.6 Å 4.9 Å ) and aperiodic 18-member ring pores (14.3 Å 7.6 Å ) due to stacking faults. [24,25,28] Additionally, ETS-10 can be synthesized using a template-free procedure which eliminates the need of sacrificing the organic structure-directing agents by calcination. [28] To the best of our knowledge, although there have been numerous attempts at utilizing zeolites and MOFs for ethylene oligomerization, gas phase ethylene oligomerization reaction in continuous mode on Ni 2 + exchanged ETS-10 (Ni-ETS-10) has not been studied before. [1,[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]29] In order to investigate the catalytic outcomes of Ni-ETS-10, two other similar microporous materials that can load divalent transition metal with significant amount -CIT-6 [30] and MOF-74 [31] were chosen. Zeolite CIT-6 has *BEA topology, but contains Zn 2 + as heteroatoms, where the framework Zn atoms generate a À2 charge per Zn. [30] The À2 charge can be used for ...

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Section: Figurementioning

confidence: 99%

Ethylene Oligomerization to Select Oligomers on Ni‐ETS‐10

2018

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“…Recent research effort has focused on the heterogeneous oligomerization of pure ethylene, using “immobilized” versions of the transition metal catalysts found in traditional homogeneous processes, such as the Shell Higher Olefin Process . The most notable are nickel complexes, supported on crystalline aluminated‐silicas, such as Al‐SBA‐15 or Al‐MCM‐41, and amorphous or crystalline alumino‐silicates, such as Siral‐30 and Zeolite Beta . Nickel species existing in these catalysts are generally considered to be isolated Ni ions in framework exchange positions.…”

Section: Introductionmentioning

confidence: 99%

Modular‐scale ethane to liquids via chemical looping oxidative dehydrogenation: Redox catalyst performance and process analysis

Neal

Haribal

McCaig

et al. 2019

J Adv Manuf & Process

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The difficulties in the liquefaction and transportation of ethane in shale gas has led to significant rejection, via reinjection or flaring, of this valuable hydrocarbon resource. Upgrading this low-value, isolated ethane into easily transportable liquid fuels is a promising solution to this supply glut. In this study, we present a modular system that can potentially be operated economically at geographically isolated gas-processing facilities. The modular ethane-to-liquids (M-ETL) system uses a chemical looping-oxidative dehydrogenation (CL-ODH) technology to efficiently convert ethane and natural gas liquids into olefins (primarily ethylene) via cyclic redox reactions of highly effective redox catalyst particles. The resulting olefins are then converted to gasoline and mid-distillate products via oligomerization. CL-ODH eliminates air separation and equilibrium limitations for olefin generation. It also simplifies the process scheme and reduces energy consumption. Here, we present experimental proof-of-concept data on CL-ODH conversion of ethane to ethylene. Using the CL-ODH performance data at 750 C, we show that a simple, single-pass configuration can be economically viable at distributed sites. We identify that economic factors such as the capital cost, price of ethane feed, and value of electricity byproduct have strong effects on the required selling price of the liquids. It is also noted that the economic viability of the M-ETL system is relatively insensitive to the liquid yield under a low ethane price scenario. The demand and value of electricity at distributed locations, on the other hand, can play an important role in the optimal process configuration and economics. K E Y W O R D Sethane, fuel, gas-to-liquids, natural gas liquids, oxidative dehydrogenation, shale gas

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“…Catalyst development for ethylene oligomerization is still an active research topic in both academia and industry. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] 2 | EXPERIMENTAL…”

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confidence: 99%

MAO‐free and extremely active catalytic system for ethylene tetramerization

Kim

Lee

Park

et al. 2019

Applied Organom Chemis

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The original Sasol catalytic system for ethylene tetramerization is composed of a Cr source, a PNP ligand, and MAO (methylaluminoxane). The use of expensive MAO in excess has been a critical concern in commercial operation. Many efforts have been made to replace MAO with non‐coordinating anions (e.g., [B(C6F5)4]−); however, most of such attempts were unsuccessful. Herein, an extremely active catalytic system that avoids the use of MAO is presented. The successive addition of two equivalent [H(OEt2)2]+[B(C6F5)4]− and one equivalent CrCl3(THF)3 to (acac)AlEt2 and subsequent treatment with a PNP ligand [CH3(CH2)16]2C(H)N(PPh2)2 (1) yielded a complex presumably formulated as [1‐CrAl (acac)Cl3(THF)]2+[B(C6F5)4]−2, which exhibited high activity when combined with iBu3Al (1120 kg/g‐Cr/h; ~4 times that of the original Sasol system composed of Cr (acac)3, iPrN(PPh2)2, and MAO). Via the introduction of bulky trialkylsilyl substituents such as –SiMe3, –Si(nBu)3, or –SiMe2(CH2)7CH3 at the para‐position of phenyl groups in 1 (i.e., by using [CH3(CH2)16]2C(H)N[P(C6H4‐p‐SiR3)2]2 instead of 1), the activities were dramatically improved, i.e., tripled (2960–3340 kg/g‐Cr/h; more than 10 times that of the original Sasol system). The generation of significantly less PE (<0.2 wt%) even at a high temperature is another advantage achieved by the introduction of bulky trialkylsilyl substituents. NMR studies and DFT calculations suggest that increase of the steric bulkiness on the alkyl‐N and P‐aryl moieties restrict the free rotation around (alkyl)N–P (aryl) bonds, which may cause the generation of more robust active species in higher proportion, leading to extremely high activity along with the generation of a smaller amount of PE.

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Nature of Active Nickel Sites and Initiation Mechanism for Ethylene Oligomerization on Heterogeneous Ni-beta Catalysts

Cited by 112 publications

References 63 publications

Ethylene Oligomerization to Select Oligomers on Ni‐ETS‐10

Ethylene Oligomerization to Select Oligomers on Ni‐ETS‐10

Modular‐scale ethane to liquids via chemical looping oxidative dehydrogenation: Redox catalyst performance and process analysis

MAO‐free and extremely active catalytic system for ethylene tetramerization

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