Abstract
The production of olefins via on-purpose dehydrogenation of alkanes allows for a more efficient, selective and lower cost alternative to processes such as steam cracking. Silica-supported pincer-iridium complexes of the form [(≡SiO−R4POCOP)Ir(CO)] (R4POCOP=κ3-C6H3-2,6-(OPR2)2) are effective for acceptorless alkane dehydrogenation, and have been shown stable up to 300 °C. However, while solution-phase analogues of such species have demonstrated high regioselectivity for terminal olefin production under transfer dehydrogenation conditions at or below 240 °C, in open systems at 300 °C, regioselectivity under acceptorless dehydrogenation conditions is consistently low. In this work, complexes [(≡SiO−tBu4POCOP)Ir(CO)] (1) and [(≡SiO−iPr4PCP)Ir(CO)] (2) were synthesized via immobilization of molecular precursors. These complexes were used for gas-phase butane transfer dehydrogenation using increasingly sterically demanding olefins, resulting in observed selectivities of up to 77 %. The results indicate that the active site is conserved upon immobilization.
Original language | English (US) |
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Pages (from-to) | 407-415 |
Number of pages | 9 |
Journal | ChemCatChem |
Volume | 13 |
Issue number | 1 |
DOIs | |
State | Published - Jan 12 2021 |
All Science Journal Classification (ASJC) codes
- Catalysis
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
Keywords
- dehydrogenation
- heterogeneous catalysis
- hydrogen transfer
- iridium
- supported catalysts