Immobilized Chromium Catalyst System for Selective Ethene Trimerization to 1‐Hexene with a PNPNH Ligand

Peulecke, Normen; Müller, Bernd; Peitz, Stephan; Aluri, Bhaskar R.; Rosenthal, Uwe; Wôhl, A.; Müller, Wolfgang; Al-Hazmi, Mohammed H.; Mosa, Fuad M.

doi:10.1002/cctc.201000087

Cited by 27 publications

(29 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While there have been numerous ethylene trimerisation studies with 1 previously reported in the literature, [21][22][23][32][33][34][35][36]38,40 it was of interest to optimise the ligand under our conditions in order to determine a series of conditions with which to benchmark the novel ligand systems. The results of catalytic testing of 1/Cr in conjunction with triethylaluminium are shown in Table 1.…”

Section: Methodsmentioning

confidence: 99%

A survey of pendant donor-functionalised (N,O) phosphine ligands for Cr-catalysed ethylene tri- and tetramerisation

Suttil

Wasserscheid

McGuinness

et al. 2014

Catal. Sci. Technol.

View full text Add to dashboard Cite

In this study three classes of ligands are explored for ethylene tri-/tetramerisation in conjunction with chromium and both triethylaluminium (AlEt 3 ) and methylaluminoxane (MAO) co-catalysts. Hydrazine based ligands containing an N-H functionality [PN(NH)P], analogous to Rosenthal's previously reported PNPNH system, show selectivity towards 1-hexene and 1-octene formation in conjunction with AlEt 3 , and act as PNP tetramerisation analogues when MAO is employed. PNP ligands containing non-protic pendant donor moieties generally show poor activity and selectivity when AlEt 3 is employed as an activator, however when MAO is used good activities and selectivities are achieved. n-Propylcyclopentane and 2-propenylcyclopentane, and higher homologues, are produced during catalysis when oxygen is the donor atom. The formation of such products is discussed with respect to the generation of methylenecyclopentane and methylcyclopentane by PNP based tetramerisation catalysts. Simple phosphine ligands containing O-H functionalisation are also explored and it was shown that the catalyst selectivity is highly dependent on both the activator and structural features of the ligand employed.

show abstract

Section: Methodsmentioning

confidence: 99%

A survey of pendant donor-functionalised (N,O) phosphine ligands for Cr-catalysed ethylene tri- and tetramerisation

Suttil

Wasserscheid

McGuinness

et al. 2014

Catal. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Nowadays it is attempted to immobilize active sites for ethene oligomerization on a heterogeneous support, hence, avoiding further catalyst separation. These active sites could be based on, e.g., nickel [5,6] or chromium [7,8]. The use of zeolites or silica-alumina as support could additionally lead to an increase in product flexibility due to the presence of both active metal ion and acid sites on such catalysts.…”

Section: Introductionmentioning

confidence: 98%

Ethene oligomerization on Ni-SiO2-Al2O3: Experimental investigation and Single-Event MicroKinetic modeling

Toch

Thybaut

Marin

2015

Applied Catalysis A: General

View full text Add to dashboard Cite

“…22 Furthermore, the tethering of chromium-based catalysts on polymeric supports has been described. 23,24 However, none of the authors comment on the morphology of the polymeric side product, catalyst leaching or reactor fouling during the oligomerization process. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 4 Here we report the immobilization of the Mitsui ethylene trimerization pre-catalyst 1 (Scheme 1), with the aim to prevent reactor fouling by homogeneous polymer formation while retaining the high trimerization activity and selectivity.…”

Section: Introductionmentioning

confidence: 98%

Effect of Aluminum Alkyls on a Homogeneous and Silica-Supported Phenoxy-Imine Titanium Catalyst for Ethylene Trimerization

2015

View full text Add to dashboard Cite

A phenoxy-imine titanium catalyst (FI-catalyst) for selective ethylene trimerization was immobilized on MAO-pretreated silica and its activity and selectivity was compared with that of the corresponding homogeneous catalyst system. The homogeneous and heterogeneous ethylene oligomerization was conducted in the presence of different aluminum alkyls, commonly used as scavengers during olefin polymerization to remove residual oxygen and moisture from the reaction medium. Both the homogeneous and heterogeneous catalysts were strongly affected by the presence of scavenger in the reaction medium. Upon activation with R 3 Al/MAO (R= Et, nOct, iBu), the homogeneous catalyst switches selectivity from ethylene trimerization to polymerization. NMR spectroscopic investigations indicate that this change of selectivity can be attributed to ligand exchange between the pre-catalyst and the aluminum alkyl. The thereby formed ligand-free titanium alkyls act as polymerization catalysts and are responsible for the increasing polymer formation. Using the heterogeneous catalyst, the scavenger employed during ethylene trimerization was found to be of crucial influence regarding the activity of the catalyst and the occurrence of reactor fouling. Employing aluminum alkyls like iBu 3 Al and nOct 3 Al resulted in catalyst leaching and homogeneous polymer formation. The latter was prevented using Me 3 Al or Et 3 Al as scavenger, however, in general the supported catalyst was poisoned by aluminum alkyls, resulting in a low overall activity. It was found to be beneficial for the heterogeneous trimerization system to employ silica-supported scavengers. By physical separation of the catalyst and the scavenger this poisoning effect was effectively prevented, resulting in a highly active heterogeneous catalyst.

show abstract

Immobilized Chromium Catalyst System for Selective Ethene Trimerization to 1‐Hexene with a PNPNH Ligand

Cited by 27 publications

References 13 publications

A survey of pendant donor-functionalised (N,O) phosphine ligands for Cr-catalysed ethylene tri- and tetramerisation

A survey of pendant donor-functionalised (N,O) phosphine ligands for Cr-catalysed ethylene tri- and tetramerisation

Ethene oligomerization on Ni-SiO2-Al2O3: Experimental investigation and Single-Event MicroKinetic modeling

Effect of Aluminum Alkyls on a Homogeneous and Silica-Supported Phenoxy-Imine Titanium Catalyst for Ethylene Trimerization

Contact Info

Product

Resources

About