Chelated amines as ligands in olefin hydrogenation catalysts

1976 ◽  
Vol 4 (2) ◽  
pp. 281-286 ◽  
Author(s):  
M. Zuber ◽  
F. Pruchnik
Keyword(s):  
Olefin Hydrogenation ◽  
Hydrogenation Catalysts

Rh2Cl2(CO)4 adsorbed and tethered on gold powder: IR spectroscopic characterization and olefin hydrogenation activity

2001 ◽  
Vol 79 (5-6) ◽  
pp. 578-586 ◽  
Author(s):  
Hanrong Gao ◽  
Robert J Angelici
Keyword(s):  
Spectroscopic Characterization ◽  
Rhodium Complexes ◽  
Olefin Hydrogenation ◽  
Hydrogenation Catalysts ◽  
Gold Powder ◽  
Ir Studies ◽  
Major Species ◽  
Catalytically Active ◽  
Unidentified Species ◽  
Diffuse Reflectance Infrared

Catalysts were prepared by adsorbing Rh2Cl2(CO)4 directly on gold powder or on gold that contained the tethered ligands 2-(diphenylphosphino)ethane-1-thiol (DPET) or methyl 2-mercaptonicotinate (MMNT). Infrared (IR) studies (diffuse reflectance infrared Fourier transform (DRIFT)) of the catalyst Rh–Au prepared by adsorbing Rh2Cl2(CO)4 directly on Au indicate that a RhI(CO)2 species is present. IR studies of Rh–DPET-Au suggest that tethered cis-Rh(DPET)(CO)2Cl is the major species at relatively high Rh2Cl2(CO)4 loadings, but trans-Rh(DPET)2(CO)Cl is observable at low Rh2Cl2(CO)4 loadings. Spectral investigations of the catalyst Rh–MMNT-Au prepared by adsorbing Rh2Cl2(CO)4 on MMNT-Au suggest that tethered [cis-Rh(MMNT)2(CO)2]+Cl– and (or) Rh(MMNT)(CO)2Cl are the major species at low Rh2Cl2(CO)4 loadings, while a new unidentified species predominates at high Rh2Cl2(CO)4 loadings. All three catalysts are active 1-hexene hydrogenation catalysts under the mild conditions of 40°C and 1 atm of H2; they are much more active than Au powder or Rh2Cl2(CO)4 in solution. Of the three catalysts, Rh–Au is the most active with a maximum turnover frequency (TOF) of 800 mol H2 per mol Rh per min while its turnover (TO) is 29 600 mol H2 per mol Rh during a 2-hour run. Under the conditions of 1-hexene hydrogenation, the catalysts lose their CO ligands. Thus, it appears that a form of Rh metal on Au is the catalytically active species.Key words: catalysis, olefin hydrogenation, gold powder, tethered rhodium complexes, infrared studies, adsorption, rhodium complexes.

EXAFS STUDY OF NICKEL AND IRON PRECURSORS OF HOMOGENEOUS ZIEGLER-TYPE HYDROGENATION CATALYSTS

1986 ◽  
Vol 47 (C8) ◽  
pp. C8-243-C8-248 ◽  
Author(s):  
C. ESSELIN ◽  
E. BAUER-GROSSE ◽  
J. GOULON ◽  
C. WILLIAMS ◽  
Y. CHAUVIN ◽  
...  
Keyword(s):  
Hydrogenation Catalysts ◽  
Exafs Study

Reaction Mechanisms of Inorganic and Organometallic Systems

2007 ◽  
Author(s):  
Robert B. Jordan
Keyword(s):  
Electron Transfer ◽  
Heterogeneous Systems ◽  
Asymmetric Hydrogenation ◽  
Pressure Effects ◽  
General Level ◽  
Hydrogenation Catalysts ◽  
Methyl Transferase ◽  
Transfer Region ◽  
Previous Edition ◽  
Oxide Synthase

This third edition retains the general level and scope of earlier editions, but has been substantially updated with over 900 new references covering the literature through 2005, and 140 more pages of text than the previous edition. In addition to the general updating of materials, there is new or greatly expanded coverage of topics such as Curtin-Hammett conditions, pressure effects, metal hydrides and asymmetric hydrogenation catalysts, the inverted electron-transfer region, intervalence electron transfer, photochemistry of metal carbonyls, methyl transferase and nitric oxide synthase. The new chapter on heterogeneous systems introduces the basic background to this industrially important area. The emphasis is on inorganic examples of gas/liquid and gas/liquid/solid systems and methods of determining heterogeneity.

scholarly journals Development and Application of Efficient Ag‐based Hydrogenation Catalysts Prepared from Rice Husk Waste

ChemCatChem ◽  
2021 ◽  
Author(s):  
Felix Unglaube ◽  
Carsten Robert Kreyenschulte ◽  
Esteban Mejía
Keyword(s):  
Rice Husk ◽  
Hydrogenation Catalysts

Intensification and optimisation of nickel recovery from spent hydrogenation catalysts via ultrasound-augmented hydrometallurgy

2021 ◽  
pp. 105771
Author(s):  
Mitchell S.W. Lim ◽  
Thomas C.K. Yang ◽  
Yeow Hong Yap ◽  
Guan-Ting Pan ◽  
Siewhui Chong ◽  
...  
Keyword(s):  
Hydrogenation Catalysts ◽  
Nickel Recovery

scholarly journals Robust and efficient hydrogenation of carbonyl compounds catalysed by mixed donor Mn(I) pincer complexes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjun Yang ◽  
Ivan Yu. Chernyshov ◽  
Robin K. A. van Schendel ◽  
Manuela Weber ◽  
Christian Müller ◽  
...  
Keyword(s):  
Noble Metal ◽  
Crucial Role ◽  
Carbonyl Compounds ◽  
Catalytic Performance ◽  
Hydrogen Atmosphere ◽  
Pincer Complexes ◽  
Catalyst Activation ◽  
Hydrogenation Catalysts ◽  
Induction Times

AbstractAny catalyst should be efficient and stable to be implemented in practice. This requirement is particularly valid for manganese hydrogenation catalysts. While representing a more sustainable alternative to conventional noble metal-based systems, manganese hydrogenation catalysts are prone to degrade under catalytic conditions once operation temperatures are high. Herein, we report a highly efficient Mn(I)-CNP pre-catalyst which gives rise to the excellent productivity (TOF° up to 41 000 h−1) and stability (TON up to 200 000) in hydrogenation catalysis. This system enables near-quantitative hydrogenation of ketones, imines, aldehydes and formate esters at the catalyst loadings as low as 5–200 p.p.m. Our analysis points to the crucial role of the catalyst activation step for the catalytic performance and stability of the system. While conventional activation employing alkoxide bases can ultimately provide catalytically competent species under hydrogen atmosphere, activation of Mn(I) pre-catalyst with hydride donor promoters, e.g. KHBEt3, dramatically improves catalytic performance of the system and eliminates induction times associated with slow catalyst activation.

scholarly journals Photo‐Initiated Cobalt Catalyzed Radical Olefin Hydrogenation

2021 ◽  
Author(s):  
Sier Sang ◽  
Tobias Unruh ◽  
Serhiy Demeshko ◽  
Luis Domenianni ◽  
Nicolaas van Leest ◽  
...  
Keyword(s):  
Olefin Hydrogenation
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