Characterization of the Surface Acidity of MFI Zeolite Nanosheets by 31P NMR of Adsorbed Phosphine Oxides and Catalytic Cracking of Decalin

ACS Catalysis ◽  
2013 ◽  
Vol 3 (4) ◽  
pp. 713-720 ◽  
Author(s):  
Yongbeom Seo ◽  
Kanghee Cho ◽  
Younjae Jung ◽  
Ryong Ryoo
Keyword(s):  
Catalytic Cracking ◽  
31P Nmr ◽  
Surface Acidity ◽  
Phosphine Oxides ◽  
Mfi Zeolite

A 31P nmr spectroscopic study of complexation of tin(II) and lead(II) by some phosphines, phosphine oxides, and related ligands, with the 31P nuclear magnetic resonance spectra of two tetratertiary phosphine tetraoxides and the analogous tetra-sulfides and -selenides

1981 ◽  
Vol 59 (1) ◽  
pp. 50-61 ◽  
Author(s):  
Philip A. W. Dean ◽  
Donald D. Phillips ◽  
Lijana Polensek
Keyword(s):  
Nmr Spectra ◽  
31P Nmr ◽  
Coupling Constants ◽  
Phosphine Oxides ◽  
Polydentate Ligands ◽  
Intramolecular Exchange ◽  
Nuclear Magnetic Resonance Spectra ◽  
Reduced Temperature

31P nmr has been used to show that, in MeNO2, M(SbF6)2 (M = Sn or Pb) forms 1:1 complexes with Ph2P(CH2)2PPh2, PhP[(CH2)2PPh2]2, MeC(CH2PPh2)3, [Formula: see text][Formula: see text]P[(CH2)2PPh2]3, and Ph2P[(CH2)2PPh]2(CH2)2PPh2. The phosphonium ligands are formed in situ. Spectra characteristics of slow inter- and intramolecular exchange were obtained in all cases except, perhaps, those involving the last two ligands, which may be involved in rapid intramolecular exchange. For the first five ligands, the maximum denticity is achieved and unambiguous one-bond M(II)—31P (M = 117/119Sn or 207Pb) coupling constants are reported and discussed. In the presence of M(SbF6)2 (M = Sn or Pb). PPh3 is protonated in MeNO2, while in acetone Sn(SbF6)2 forms a 1:1 complex with PPh3 which appears to be solvent-inserted, [Sn—O—CMe2PPh3]2+.Reduced temperature 31P nmr spectroscopy has allowed the detection of 1:2 and 1:3 (M:L) complexes of OPPh3, and 1:1 complexes of Ph2P(O)(CH2)2P(O)Ph2, PhP(O)[(CH2)2P(O)Ph2]2, and (O)P[(CH2)2P(O)Ph2]3, with both tin(II) and lead(II). The 1:1 complexes with polydentate ligands are isolable; nmr shows that the maximum denticity occurs except with the last ligand which behaves in a tridentate manner. Several two-bond M—O—P coupling constants have been obtained. Also, the changes which complexation produces in the P—P couplings are compared with changes produced in the analogous phosphine complexes.The synthesis and characterization of Ph2P(E)[(CH2)2P(E)Ph]2(CH2)2P(E)Ph2 (E = S or Se) and (Se)P[(CH2)2P(Se)Ph2]3 are reported. The 31P nmr spectra of these compounds are compared with those of the parent tetraphosphines and other members of the corresponding tetraoxide–tetrachalcogenide series.

Synthesis and characterization of Ce doped MFI zeolite

2012 ◽  
Vol 133 (2-3) ◽  
pp. 713-717 ◽  
Author(s):  
Banani Kalita ◽  
Anup K. Talukdar
Keyword(s):  
Synthesis And Characterization ◽  
Mfi Zeolite

scholarly journals Production and Characterization of Green gasoline Obtained by Thermal Catalytic Cracking of Crude Palm Oil (Elaeis guineensis, Jacq.) in a Pilot Plant

2017 ◽  
Vol 13 (01) ◽  
Author(s):  
Silvio Alex Pereira Mota ◽  
Andréia De Andrade Mancio ◽  
Luiz Eduardo Pizarro Borges ◽  
Nélio Teixeira Machado
Keyword(s):  
Palm Oil ◽  
Catalytic Cracking ◽  
Pilot Plant ◽  
Elaeis Guineensis ◽  
Crude Palm Oil ◽  
Elaeis Guineensis Jacq

Characterization of soil phosphorus in a fire-affected forest Cambisol by chemical extractions and 31P-NMR spectroscopy analysis

2010 ◽  
Vol 408 (16) ◽  
pp. 3342-3348 ◽  
Author(s):  
María-Belén Turrion ◽  
Francisco Lafuente ◽  
María-José Aroca ◽  
Olga López ◽  
Rafael Mulas ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
31P Nmr ◽  
Soil Phosphorus ◽  
31P Nmr Spectroscopy ◽  
Spectroscopy Analysis ◽  
Chemical Extractions

scholarly journals Determination of Catalyst Surface Acidity in Liquids by a Pulse Liquid Chromatographic Technique

2005 ◽  
Vol 23 (9) ◽  
pp. 739-749 ◽  
Author(s):  
Paolo Carniti ◽  
Antonella Gervasini ◽  
Serena Biella
Keyword(s):  
Surface Acidity ◽  
Lower Amount ◽  
Chromatographic Technique ◽  
Solvent Flow Rate ◽  
Acidic Sites ◽  
Catalyst Acidity ◽  
Set Up ◽  
Liquid Chromatographic

A pulse liquid chromatographic technique, set up by using an HPLC apparatus, is proposed for the characterization of the surface acidity of solid acids in liquids in view of their use as catalysts in liquid–solid reactions. Dosed amounts of solutions of two different basic probe molecules (2-phenylethylamine, pKa = 9.84 and aniline, pKa = 4.63) in solvents of different polarity were injected onto solid samples (acidic resins, Amberlites and a mixed silica–zirconia oxide) at a constant solvent flow rate. Titration with the weakest basic probe (aniline) rather than 2-phenylethylamine generally led to a lower amount of acidic sites. The amount of acidic sites determined at the surface was greatly affected by the solvent. With silica–zirconia, a higher amount of acidic sites was established by titration in apolar rather than polar solvents. The results have been compared with those obtained by conventional methods, i.e. ion exchange employing salts and, for silica–zirconia, Hammett titrations. The quite satisfactory results obtained are of some importance in establishing valuable relationships between catalyst acidity and catalytic activity in various solvents.

scholarly journals Synthesis and Spectroscopic Characterization of Two New Dawson Sandwich Complexes: Na18[(NaOH)2(VO)2(P2W15O56)2].40H2O and Na18[(NaOH)2(VO)2(As2W15O56)2].27H2O

2012 ◽  
Vol 9 (4) ◽  
pp. 2185-2190 ◽  
Author(s):  
Mohammad Hakimi ◽  
Mohammad Reza Mohammadi ◽  
Salma Behboupour
Keyword(s):  
Divalent Cation ◽  
31P Nmr ◽  
Spectroscopic Characterization ◽  
Sandwich Complexes ◽  
Sandwich Complex ◽  
Sodium Salts ◽  
Vis Spectroscopy ◽  
Sandwich Type ◽  
Anion Complexes

Reaction of the three vacant complex ofa-[P2W15O56]12-anda-[As2W15O56]12-with divalent cation of VO2+in 1:1 mole ratio yields a previously unknown sandwich-type Wells-Dawson complex; Na18[(NaOH)2(VO)2(P2W15O56)2].40H2O (represented as Na2(VO)2P4W30) and Na18[(NaOH)2(VO)2(As2W15O56)2].27H2O (represented as Na2(VO)2As4W30). These complexes contain anions in which two divalent VO2+cations with two Na+ions are symmetrically sandwiched between two α-[P2W15O56]12- or α-[As2W15O56]12-groups leading to a “lacunary” sandwich complex. The anion complexes are isolated as sodium salts and characterized by elemental analysis, TGA, IR, 31P NMR and UV-Vis spectroscopy.

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