Rationalizing kinetic behaviors of isolated boron sites catalyzed oxidative dehydrogenation of propane.

ABSTRACT: Boron-based catalysts exhibit high alkene selectivity in oxidative dehydrogenation of propane (ODHP) but the mechanistic understanding remains incomplete. In this work, we show that the hydroxylation of framework boron species via steaming not only enhances the ODHP rate on both B-MFI and B-BEA, but also impacts the kinetics of the reaction. The altered activity, propane reaction order and the activation energy could be attributed to the hydrolysis of framework [B(OSi≡)₃] unit to [B(OSi≡)_3-x(OH···O(H)Si≡)_x] (x = 1, 2, "···" represents hydrogen bonding). DFT calculations confirm that hydroxylated framework boron sites could stabilize radical species, e.g., hydroperoxyl radical, further facilitating the gas-phase radical mechanism. Variations in the contribut

SUBMITTER: Tian H 

PROVIDER: S-EPMC10579386 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature