Matches in SemOpenAlex for { <https://semopenalex.org/work/W2029383408> ?p ?o ?g. }
Showing items 1 to 98 of
98
with 100 items per page.
- W2029383408 endingPage "221" @default.
- W2029383408 startingPage "195" @default.
- W2029383408 abstract "The synthesis of higher (C+2) alcohols and esters has been studied over cesium-doped CuZnO catalysts. Under higher alcohol synthesis conditions, e.g., 583 K, 7.6 MPa, and gas hourly space velocity = 3260 liters (STP)/kg cat/hr with a H2CO = 0.45 synthesis gas, the presence of cesium promoted the formation of higher oxygenates, especially 2-methyl-1-propanol. The yields of products passed through distinct maxima at cesium nominal concentrations of 0.3–0.5%. These nominal concentrations generated optimum surface cesium concentrations of 15–25%. Under the reaction conditions employed, the principal role of cesium was to increase the ethanol synthesis rate and to provide an even greater enhancement in the rate of ethanol conversion to 1-propanol and subsequently to higher alcohols. To obtain insight into the mechanism of the carbon chain growth, e.g., C1 → C2, C2 → C3, and linear versus branched carbon chain growth, a 13C-NMR study of the C2C4 products formed over CuZnO and 0.4 mol% Cs/Cu/ZnO catalysts was performed. Separate injections into the COH2 synthesis gas of methanol and ethanol with natural-abundance 13C and enriched by 13C in specific positions showed that (i) lower alcohols were incorporated into the synthesis to form higher alcohols; (ii) carbon chain growth occurred in a stepwise manner dominated by the addition of oxygenated C1 intermediates at the β carbons of the oxygenated Cn (n ≥ 2) intermediates but also proceeding via linear addition Cn + C1 (n ≥ 1); and (iii) the presence of cesium had a dramatic effect on the reaction mechanism and promoted greatly the synthesis rates. The mechanistic effects of the alkali dopant were most pronounced in the C2 → C3 step. Over the CuZnO catalyst, injection of ethanol produced 1-propanol via linear chain growth, i.e., CH313CH2OH + COH2 → CH313CH2CH2OH. The presence of Cs effected a mechanistic switch and promoted β-carbon addition, CH313CH2OH + COH2 → 13CH3CH2CH2OH. The position of the 13C label in the CH3 group of propanol provides evidence for retention of oxygen associated with the C1 intermediate, formed from COH2, and loss of oxygen associated with the 13CH2OH group of ethanol. Mechanistically, such a retention is favored by a β-ketoalkoxide intermediate that is bonded to the cesium centers via its anionic oxygen. This unique mechanism is termed herein as aldol coupling with oxygen retention reversal and is specific to the presence of the cesium salt dopant. Higher alcohol synthetic steps C2 + C2 and Cn + Cm (n ≥ 3, m = 1, 2, 3) were also analyzed. Both oxygen retention reversal and normal oxygen retention were observed in coupling reactions leading to the higher-molecular-weight products (m + n > 3), and this observation is attributed to steric effects favoring the cis conformation of the β-alkoxide followed by rejection of either of its two oxygens." @default.
- W2029383408 created "2016-06-24" @default.
- W2029383408 creator A5003355274 @default.
- W2029383408 creator A5014057273 @default.
- W2029383408 creator A5032108373 @default.
- W2029383408 creator A5036887828 @default.
- W2029383408 creator A5045221560 @default.
- W2029383408 creator A5063136693 @default.
- W2029383408 date "1989-03-01" @default.
- W2029383408 modified "2023-10-18" @default.
- W2029383408 title "Higher alcohol and oxygenate synthesis over cesium-doped Cu/Zno catalysts" @default.
- W2029383408 cites W132354691 @default.
- W2029383408 cites W1964992666 @default.
- W2029383408 cites W1965566776 @default.
- W2029383408 cites W1995991279 @default.
- W2029383408 cites W2001230391 @default.
- W2029383408 cites W2007935457 @default.
- W2029383408 cites W2034357820 @default.
- W2029383408 cites W2035279608 @default.
- W2029383408 cites W2041043074 @default.
- W2029383408 cites W2049879966 @default.
- W2029383408 cites W2065829323 @default.
- W2029383408 cites W2066165814 @default.
- W2029383408 cites W2067979843 @default.
- W2029383408 cites W2071192557 @default.
- W2029383408 cites W2087057184 @default.
- W2029383408 cites W572591534 @default.
- W2029383408 cites W644853776 @default.
- W2029383408 cites W66354410 @default.
- W2029383408 doi "https://doi.org/10.1016/0021-9517(89)90086-9" @default.
- W2029383408 hasPublicationYear "1989" @default.
- W2029383408 type Work @default.
- W2029383408 sameAs 2029383408 @default.
- W2029383408 citedByCount "167" @default.
- W2029383408 countsByYear W20293834082012 @default.
- W2029383408 countsByYear W20293834082013 @default.
- W2029383408 countsByYear W20293834082014 @default.
- W2029383408 countsByYear W20293834082015 @default.
- W2029383408 countsByYear W20293834082016 @default.
- W2029383408 countsByYear W20293834082017 @default.
- W2029383408 countsByYear W20293834082018 @default.
- W2029383408 countsByYear W20293834082019 @default.
- W2029383408 countsByYear W20293834082021 @default.
- W2029383408 countsByYear W20293834082022 @default.
- W2029383408 crossrefType "journal-article" @default.
- W2029383408 hasAuthorship W2029383408A5003355274 @default.
- W2029383408 hasAuthorship W2029383408A5014057273 @default.
- W2029383408 hasAuthorship W2029383408A5032108373 @default.
- W2029383408 hasAuthorship W2029383408A5036887828 @default.
- W2029383408 hasAuthorship W2029383408A5045221560 @default.
- W2029383408 hasAuthorship W2029383408A5063136693 @default.
- W2029383408 hasConcept C104779481 @default.
- W2029383408 hasConcept C108285982 @default.
- W2029383408 hasConcept C140205800 @default.
- W2029383408 hasConcept C159985019 @default.
- W2029383408 hasConcept C161790260 @default.
- W2029383408 hasConcept C178790620 @default.
- W2029383408 hasConcept C179104552 @default.
- W2029383408 hasConcept C185592680 @default.
- W2029383408 hasConcept C192562407 @default.
- W2029383408 hasConcept C2779607525 @default.
- W2029383408 hasConcept C2780161600 @default.
- W2029383408 hasConcept C2781066024 @default.
- W2029383408 hasConcept C519659679 @default.
- W2029383408 hasConceptScore W2029383408C104779481 @default.
- W2029383408 hasConceptScore W2029383408C108285982 @default.
- W2029383408 hasConceptScore W2029383408C140205800 @default.
- W2029383408 hasConceptScore W2029383408C159985019 @default.
- W2029383408 hasConceptScore W2029383408C161790260 @default.
- W2029383408 hasConceptScore W2029383408C178790620 @default.
- W2029383408 hasConceptScore W2029383408C179104552 @default.
- W2029383408 hasConceptScore W2029383408C185592680 @default.
- W2029383408 hasConceptScore W2029383408C192562407 @default.
- W2029383408 hasConceptScore W2029383408C2779607525 @default.
- W2029383408 hasConceptScore W2029383408C2780161600 @default.
- W2029383408 hasConceptScore W2029383408C2781066024 @default.
- W2029383408 hasConceptScore W2029383408C519659679 @default.
- W2029383408 hasIssue "1" @default.
- W2029383408 hasLocation W20293834081 @default.
- W2029383408 hasOpenAccess W2029383408 @default.
- W2029383408 hasPrimaryLocation W20293834081 @default.
- W2029383408 hasRelatedWork W140851365 @default.
- W2029383408 hasRelatedWork W1483123004 @default.
- W2029383408 hasRelatedWork W1607908441 @default.
- W2029383408 hasRelatedWork W2074052481 @default.
- W2029383408 hasRelatedWork W2088249402 @default.
- W2029383408 hasRelatedWork W2370126060 @default.
- W2029383408 hasRelatedWork W2373611490 @default.
- W2029383408 hasRelatedWork W2403322145 @default.
- W2029383408 hasRelatedWork W4247378629 @default.
- W2029383408 hasRelatedWork W807722370 @default.
- W2029383408 hasVolume "116" @default.
- W2029383408 isParatext "false" @default.
- W2029383408 isRetracted "false" @default.
- W2029383408 magId "2029383408" @default.
- W2029383408 workType "article" @default.