FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2027362160> ?p ?o ?g. }

• W2027362160 endingPage "11473" @default.
• W2027362160 startingPage "11462" @default.
• W2027362160 abstract "The depth of our understanding in catalysis is governed by the information we have about the number of active sites and their molecular structure. The nature of an active center on the surface of a working heterogeneous catalyst is, however, extremely difficult to identify and precise quantification of active species is generally missing. In metathesis of propene over dispersed molybdenum oxide supported on silica, only 1.5% of all Mo atoms in the catalyst are captured to form the active centers. Here we combine infrared spectroscopy in operando with microcalorimetry and reactivity studies using isotopic labeling to monitor catalyst formation. We show that the active Mo(VI)-alkylidene moieties are generated in situ by surface reaction of grafted molybdenum oxide precursor species with the substrate molecule itself gaining insight into the pathways limiting the number of active centers on the surface of a heterogeneous catalyst. The active site formation involves sequential steps requiring multiple catalyst functions: protonation of propene to surface Mo(VI)-isopropoxide species driven by surface Brønsted acid sites, subsequent oxidation of isopropoxide to acetone in the adsorbed state owing to the red-ox capability of molybdenum leaving naked Mo(IV) sites after desorption of acetone, and oxidative addition of another propene molecule yielding finally the active Mo(VI)-alkylidene species. This view is quite different from the one-step mechanism, which has been accepted in the community for three decades, however, fully consistent with the empirically recognized importance of acidity, reducibility, and strict dehydration of the catalyst. The knowledge acquired in the present work has been successfully implemented for catalyst improvement. Simple heat treatment after the initial propene adsorption doubled the catalytic activity by accelerating the oxidation and desorption-capturing steps, demonstrating the merit of knowledge-based strategies in heterogeneous catalysis. Molecular structure of active Mo(VI)-alkylidene sites derived from surface molybdena is discussed in the context of similarity to the highly active Schrock-type homogeneous catalysts." @default.
• W2027362160 created "2016-06-24" @default.
• W2027362160 creator A5002594652 @default.
• W2027362160 creator A5010271376 @default.
• W2027362160 creator A5036649608 @default.
• W2027362160 creator A5065894642 @default.
• W2027362160 creator A5072582193 @default.
• W2027362160 creator A5079594212 @default.
• W2027362160 date "2012-07-06" @default.
• W2027362160 modified "2023-09-29" @default.
• W2027362160 title "In Situ Generation of Active Sites in Olefin Metathesis" @default.
• W2027362160 cites W1676225962 @default.
• W2027362160 cites W1702377871 @default.
• W2027362160 cites W1965503345 @default.
• W2027362160 cites W1967328769 @default.
• W2027362160 cites W1968956136 @default.
• W2027362160 cites W1971744572 @default.
• W2027362160 cites W1972723858 @default.
• W2027362160 cites W1976543758 @default.
• W2027362160 cites W1979128782 @default.
• W2027362160 cites W1979429751 @default.
• W2027362160 cites W1980996049 @default.
• W2027362160 cites W1991536381 @default.
• W2027362160 cites W1993892680 @default.
• W2027362160 cites W1995041236 @default.
• W2027362160 cites W1996232383 @default.
• W2027362160 cites W1999887307 @default.
• W2027362160 cites W2000339942 @default.
• W2027362160 cites W2000569739 @default.
• W2027362160 cites W2003800623 @default.
• W2027362160 cites W2005015509 @default.
• W2027362160 cites W2006428588 @default.
• W2027362160 cites W2008468227 @default.
• W2027362160 cites W2010242541 @default.
• W2027362160 cites W2012021969 @default.
• W2027362160 cites W2014561421 @default.
• W2027362160 cites W2015238312 @default.
• W2027362160 cites W2018994643 @default.
• W2027362160 cites W2019450102 @default.
• W2027362160 cites W2020419767 @default.
• W2027362160 cites W2023716594 @default.
• W2027362160 cites W2034382476 @default.
• W2027362160 cites W2035882383 @default.
• W2027362160 cites W2038662926 @default.
• W2027362160 cites W2042077235 @default.
• W2027362160 cites W2042769004 @default.
• W2027362160 cites W2048796469 @default.
• W2027362160 cites W2049544345 @default.
• W2027362160 cites W2050881509 @default.
• W2027362160 cites W2055118674 @default.
• W2027362160 cites W2056480972 @default.
• W2027362160 cites W2057153244 @default.
• W2027362160 cites W2063097280 @default.
• W2027362160 cites W2063454667 @default.
• W2027362160 cites W2066280956 @default.
• W2027362160 cites W2066922850 @default.
• W2027362160 cites W2068745671 @default.
• W2027362160 cites W2071912839 @default.
• W2027362160 cites W2072068961 @default.
• W2027362160 cites W2072442647 @default.
• W2027362160 cites W2076068838 @default.
• W2027362160 cites W2081854580 @default.
• W2027362160 cites W2083040485 @default.
• W2027362160 cites W2089088975 @default.
• W2027362160 cites W2094884004 @default.
• W2027362160 cites W2102381420 @default.
• W2027362160 cites W2104416339 @default.
• W2027362160 cites W2105633570 @default.
• W2027362160 cites W2115437430 @default.
• W2027362160 cites W2118275961 @default.
• W2027362160 cites W2145241357 @default.
• W2027362160 cites W2148748101 @default.
• W2027362160 cites W2152679587 @default.
• W2027362160 cites W2156837791 @default.
• W2027362160 cites W2314104404 @default.
• W2027362160 cites W2488282360 @default.
• W2027362160 cites W2615993099 @default.
• W2027362160 cites W4240604186 @default.
• W2027362160 cites W4247297545 @default.
• W2027362160 cites W4250478611 @default.
• W2027362160 cites W76674442 @default.
• W2027362160 doi "https://doi.org/10.1021/ja3011989" @default.
• W2027362160 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/22703234" @default.
• W2027362160 hasPublicationYear "2012" @default.
• W2027362160 type Work @default.
• W2027362160 sameAs 2027362160 @default.
• W2027362160 citedByCount "129" @default.
• W2027362160 countsByYear W20273621602013 @default.
• W2027362160 countsByYear W20273621602014 @default.
• W2027362160 countsByYear W20273621602015 @default.
• W2027362160 countsByYear W20273621602016 @default.
• W2027362160 countsByYear W20273621602017 @default.
• W2027362160 countsByYear W20273621602018 @default.
• W2027362160 countsByYear W20273621602019 @default.
• W2027362160 countsByYear W20273621602020 @default.
• W2027362160 countsByYear W20273621602021 @default.
• W2027362160 countsByYear W20273621602022 @default.
• W2027362160 countsByYear W20273621602023 @default.

• next