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Volumn 27, Issue 10, 2011, Pages 6279-6294

Industrial ziegler-type hydrogenation catalysts made from Co(neodecanoate)2 or Ni(2-ethylhexanoate)2 and AlEt 3: Evidence for nanoclusters and sub-nanocluster or larger ziegler-nanocluster based catalysis

Author keywords

[No Author keywords available]

Indexed keywords

ACTIVE CATALYST; ANALYTICAL METHOD; CATALYST SYNTHESIS; CATALYST SYSTEM; CATALYTIC HYDROGENATION; CLUSTER DIAMETER; CRITICAL REVIEW; CYCLOHEXENE HYDROGENATION; DISTRIBUTION OF METAL; HYDROGENATION CATALYSIS; HYDROGENATION CATALYST; INDUSTRIAL PRECURSORS; INDUSTRIAL PROCESSS; IR MODELS; KINETIC STUDY; MALDI-MS; MATRIX-ASSISTED LASER DESORPTION IONIZATION MASS SPECTROMETRY; METAL CLUSTER; MICROSCOPIC ANALYSIS; MONOMETALLIC COMPLEX; NANOMETER-SCALE PARTICLES; NI-BASED CATALYST; POLYMERIZATION CATALYSTS; PRECATALYSTS; SELECTIVE HYDROGENATION; STYRENIC BLOCK COPOLYMERS; SUBNANOMETERS; X RAY ABSORPTION FINE STRUCTURES; XAFS; Z-CONTRAST SCANNING;

EID: 79958179276     PISSN: 07437463     EISSN: 15205827     Source Type: Journal    
DOI: 10.1021/la200053f     Document Type: Article
Times cited : (23)

References (78)
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    • Studies by Bönnemann and co-workers do not focus on hydrogenation catalysis using Ziegler-type systems, but do demonstrate the synthesis and identification of nanoclusters from Ni or Pt Zieglertype systems.
    • Studies by Bönnemann and co-workers do not focus on hydrogenation catalysis using Ziegler-type systems, but do demonstrate the synthesis and identification of nanoclusters from Ni or Pt Zieglertype systems.
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    • Catalyst samples, both before and after hydrogenation, were also analyzed using bright field and high resolutuion (HR)TEM as control experiments. Images and a short discussion of those results can be found in the Supporting Information
    • Catalyst samples, both before and after hydrogenation, were also analyzed using bright field and high resolutuion (HR)TEM as control experiments. Images and a short discussion of those results can be found in the Supporting Information.
  • 52
    • 79958112420 scopus 로고    scopus 로고
    • Since much of the other data presented herein is for the Al/Ni = 2.0 catalyst, we carefully considered if it was important to have higher quality data for the Al/Ni = 2.0 sample in order to support the conclusions in the present study. We reasoned that such data are not necessary, primarily on the basis of the following four reasons
    • Since much of the other data presented herein is for the Al/Ni = 2.0 catalyst, we carefully considered if it was important to have higher quality data for the Al/Ni = 2.0 sample in order to support the conclusions in the present study. We reasoned that such data are not necessary, primarily on the basis of the following four reasons.
  • 53
    • 79958172143 scopus 로고    scopus 로고
    • First, the XANES spectra of these samples show a smooth progression of the samples from the Al/Ni = 1.0 to Al/Ni = 3.0 ratios. Second, there is considerable similarity between the Al/Ni = 2.0 and 3.0 spectra when plotted as ζ(k), and despite the additional noise apparent in the Al/Ni = 2.0 sample (relevant spectra comparisons are given in the Supporting Information). Third, these first two observations, together with the similarity between the fitting results from catalyst samples with Al/Ni ratios of 1.0 and 3.0, demonstrate that reliable fitting results for the Al/Ni = 2.0 sample should have values between those obtained from the Al/Ni = 1.0 and 3.0 samples
    • First, the XANES spectra of these samples show a smooth progression of the samples from the Al/Ni = 1.0 to Al/Ni = 3.0 ratios. Second, there is considerable similarity between the Al/Ni = 2.0 and 3.0 spectra when plotted as ζ(k), and despite the additional noise apparent in the Al/Ni = 2.0 sample (relevant spectra comparisons are given in the Supporting Information). Third, these first two observations, together with the similarity between the fitting results from catalyst samples with Al/Ni ratios of 1.0 and 3.0, demonstrate that reliable fitting results for the Al/Ni = 2.0 sample should have values between those obtained from the Al/Ni = 1.0 and 3.0 samples. And fourth, the interpretation of the XAFS data herein, that 1NN M-M coordination numbers are not representative of cluster nuclearity, means that a direct comparison between the results from XAFS and cluster size measurements using other methods such as Z-contrast STEM is not straightforward; this is the case even if higher quality data for the Al/Ni = 2.0 sample were in hand. In short, obtaining higher quality data for the Al/Ni = 2.0 sample is not expected to improve or change any of the conclusions reached in the present study.
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    • 79958118165 scopus 로고    scopus 로고
    • One possible interpretation is that M̃4-6 clusters remain tightly associated (i.e., (M̃4-6)n). For some precedent for this
    • One possible interpretation is that M̃4-6 clusters remain tightly associated (i.e., (M̃4-6)n). For some precedent for this
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    • n clusters have a greater thermodynamic tendency to agglomerate to the thermodynamic minimum of a bulk Ir(0) mirror compared to Co(0) or Ni(0) clusters. The presence of hydrides or surface ligands, such as in a putativeM4H4Ly, mitigates this driving force some, however, since Ir-H and Ir-L bond energies should be stronger than Co or Ni ones
    • n clusters have a greater thermodynamic tendency to agglomerate to the thermodynamic minimum of a bulk Ir(0) mirror compared to Co(0) or Ni(0) clusters. The presence of hydrides or surface ligands, such as in a putativeM4H4Ly, mitigates this driving force some, however, since Ir-H and Ir-L bond energies should be stronger than Co or Ni ones.
  • 77
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    • A useful reference on this point is: Kilic C
    • A useful reference on this point is: Kilic, C. Solid State Commun. 2010, 150, 2333-2336.
    • (2010) Solid State Commun. , vol.150 , pp. 2333-2336
  • 78
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    • The difference in aging effects on the catalysts, the Ir system becoming faster, while aging the Co and Ni catalysts for 24 h has either a slight or significant slowing effect, respectively, (see the Supporting Information) is noteworthy here, and shows an important difference in the Co and Ni versus Ir samples. This difference, in turn, suggests that characterization of the Co and Ni samples as a function of aging is an important future goal-that aged material is not the best catalyst
    • The difference in aging effects on the catalysts, the Ir system becoming faster, while aging the Co and Ni catalysts for 24 h has either a slight or significant slowing effect, respectively, (see the Supporting Information) is noteworthy here, and shows an important difference in the Co and Ni versus Ir samples. This difference, in turn, suggests that characterization of the Co and Ni samples as a function of aging is an important future goal-that aged material is not the best catalyst.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.