Matches in SemOpenAlex for { <https://semopenalex.org/work/W987370367> ?p ?o ?g. }
Showing items 1 to 77 of
77
with 100 items per page.
- W987370367 abstract "This thesis reports on investigations into the potential uses of the perfluorinated ionexchange polymer NAFION as a catalyst support and as a Bronsted acid co-catalyst. Research has been undertaken with the aim of supporting complexes which are active homogeneous catalysts as well as investigating the formation of metal particle catalysts within NAFION. Four methods of immobilizing potential catalysts based on ionic interactions or physicalli entrapment have been tested and found successful. These were: (i) immobilization of Pd(N N) 2 2+ species by simple ion-exchange,(ii) activation of Ni[P(OEt)3]4 with NAFION-H+ to yield the cationic hydridespecies HNi[P(0E0 3]4+,(iii) replacement of Br and a PPh3 in Ni(o-toly1)Br(PPh3)2 with pyridine toproduce the cationic Ni(o-toly1)(py) 2PPh3+ species, and(iv) immobilization of metallic Pt within NAFION by in-situ reduction ofPt(NH3 )42+. Complexes of the type Pd(N N)2X2, where N N is a chelating nitrogen donor ligand, e.g. 1,10-phenanthroline, and X is a non-coordinating anion, have previously been found to dimerize ethene. Such Pd complexes are easily supported within NAFION by ion-exchange. Attempts to use the supported Pd complexes as ethene dimerization catalysts initially met with limited success with activities being about 10 % of similar homogeneous catalyst activities. However, after undertaking further studies it was found that activities comparable with the homogeneous catalyst could be obtained by decreasing the catalyst loading in NAFION. The effects of ligand, solvent, temperature and pressure on catalytic activity have also been studied.The use of acid-NAFION as a Bronsted acid co-catalyst and support has been investigated. The Ni[P(OEt) 3]4complex was previously reported to isomerize 1-butene when activated with a BrOnsted acid. The proposed catalytic species is the HNi[P(OEt)3] 3+ cation. Experiments were undertaken in which 1-octene and 1-butene were isomerized by acid-NAFION / Ni[P(OEt)3]4systems. The NAFION not only functioned as the co-catalyst, but also supported the active catalyst. Diffusion restrictions were found to severely limit the 1-octene isomerization rate using the NAFION supported catalyst. The use of organonickel species activated by alkylaluminiums as oligomerization catalysts is an area which has received much attention in the past. It is however possible to activate organonickel species containing halides by treatment with Ag+ or T1+ salts to remove the halide anion. The replacement of the halide anion in such species by a neutral ligand, e.g. pyridine, has also produced a cationic Ni species. Immobilization of a cationic organonickel species using this method was successfully achieved. Catalytic testing was undertaken but the use of chlorobenzene as solvent prevented the NAFION from swelling and resulted in the activity of the supported catalyst being much less than the homogeneous species. Platinum particles have been immobilized in NAFION and have shown activity as hydrogenation catalysts. Characterization of the particles was difficult as determination of the metal dispersion was not possible using techniques such as chemisorption of CO, adsorption of r from solution or using cyclic voltammetry. TEM and X-ray line broadening analysis did however indicate that the Pt was distributed as a thin layer along the NAFION edge with the average particle size ca. 40 A. A plot of cyclohexene hydrogenation rate vs Pt loading in NAFION suggested that above 2.5 % wt/wt Pt the additional Pt was inaccessible." @default.
- W987370367 created "2016-06-24" @default.
- W987370367 creator A5020900880 @default.
- W987370367 date "1992-01-01" @default.
- W987370367 modified "2023-09-27" @default.
- W987370367 title "Investigation of the perfluorinated polymer NAFION as a catalyst support" @default.
- W987370367 hasPublicationYear "1992" @default.
- W987370367 type Work @default.
- W987370367 sameAs 987370367 @default.
- W987370367 citedByCount "0" @default.
- W987370367 crossrefType "dissertation" @default.
- W987370367 hasAuthorship W987370367A5020900880 @default.
- W987370367 hasConcept C109474758 @default.
- W987370367 hasConcept C116569031 @default.
- W987370367 hasConcept C147789679 @default.
- W987370367 hasConcept C154881586 @default.
- W987370367 hasConcept C15920480 @default.
- W987370367 hasConcept C161790260 @default.
- W987370367 hasConcept C170493617 @default.
- W987370367 hasConcept C17525397 @default.
- W987370367 hasConcept C178790620 @default.
- W987370367 hasConcept C179104552 @default.
- W987370367 hasConcept C183882617 @default.
- W987370367 hasConcept C185592680 @default.
- W987370367 hasConcept C188027245 @default.
- W987370367 hasConcept C2776171763 @default.
- W987370367 hasConcept C2778665636 @default.
- W987370367 hasConcept C2779485729 @default.
- W987370367 hasConcept C521977710 @default.
- W987370367 hasConcept C52859227 @default.
- W987370367 hasConcept C55493867 @default.
- W987370367 hasConceptScore W987370367C109474758 @default.
- W987370367 hasConceptScore W987370367C116569031 @default.
- W987370367 hasConceptScore W987370367C147789679 @default.
- W987370367 hasConceptScore W987370367C154881586 @default.
- W987370367 hasConceptScore W987370367C15920480 @default.
- W987370367 hasConceptScore W987370367C161790260 @default.
- W987370367 hasConceptScore W987370367C170493617 @default.
- W987370367 hasConceptScore W987370367C17525397 @default.
- W987370367 hasConceptScore W987370367C178790620 @default.
- W987370367 hasConceptScore W987370367C179104552 @default.
- W987370367 hasConceptScore W987370367C183882617 @default.
- W987370367 hasConceptScore W987370367C185592680 @default.
- W987370367 hasConceptScore W987370367C188027245 @default.
- W987370367 hasConceptScore W987370367C2776171763 @default.
- W987370367 hasConceptScore W987370367C2778665636 @default.
- W987370367 hasConceptScore W987370367C2779485729 @default.
- W987370367 hasConceptScore W987370367C521977710 @default.
- W987370367 hasConceptScore W987370367C52859227 @default.
- W987370367 hasConceptScore W987370367C55493867 @default.
- W987370367 hasLocation W9873703671 @default.
- W987370367 hasOpenAccess W987370367 @default.
- W987370367 hasPrimaryLocation W9873703671 @default.
- W987370367 hasRelatedWork W1597333855 @default.
- W987370367 hasRelatedWork W1965112958 @default.
- W987370367 hasRelatedWork W1975109368 @default.
- W987370367 hasRelatedWork W2035609428 @default.
- W987370367 hasRelatedWork W2075353887 @default.
- W987370367 hasRelatedWork W2077709599 @default.
- W987370367 hasRelatedWork W2110962742 @default.
- W987370367 hasRelatedWork W2164735267 @default.
- W987370367 hasRelatedWork W2170511867 @default.
- W987370367 hasRelatedWork W2171912186 @default.
- W987370367 hasRelatedWork W2192839940 @default.
- W987370367 hasRelatedWork W2882991996 @default.
- W987370367 hasRelatedWork W2886463580 @default.
- W987370367 hasRelatedWork W2890975273 @default.
- W987370367 hasRelatedWork W2921871997 @default.
- W987370367 hasRelatedWork W2952769307 @default.
- W987370367 hasRelatedWork W2952984520 @default.
- W987370367 hasRelatedWork W2972588502 @default.
- W987370367 hasRelatedWork W3011652123 @default.
- W987370367 hasRelatedWork W362565313 @default.
- W987370367 isParatext "false" @default.
- W987370367 isRetracted "false" @default.
- W987370367 magId "987370367" @default.
- W987370367 workType "dissertation" @default.