Reaction Energy Landscape of Propane Oxidative Dehydrogenation on Liquid Boron Oxide‐Germinated Catalytic Sites in the Presence of Dioxygen: An Orbitals‐Driven Mechanistic Study

Recently, boron‐based catalysts have gained significant attention for the oxidative dehydrogenation of propane into propene and ethene. In this study, we present an electronic‐level understanding of propane oxidation via a triplet dioxygen molecule over liquid boron oxide motifs, including cyclic B−O−B sites (8‐, 6‐, and 4‐membered rings) and edge B−OH and B−B sites. Our computations reveal that cyclic B−O−B and edge B−OH motifs exhibit higher activation barriers for C 3 H 6 (55–71 kcal mol −1 ) and C 2 H 4 (80–95 kcal mol −1 ) formation. In contrast, the B−B site requires the lowest barrier among all sites. Orbital analysis reveals that 3 O 2 activation at cyclic B−O−B sites proceeds via an electron transfer from O(2p) orbital into the antibonding orbitals of 3 O 2 . Over edge B−OH sites, the σ(O−H) bonding orbital facilitates 3 O 2 activation. At the B−B site, the σ(B−B) bonding orbital transfers an electron into the antibonding orbital of 3 O 2 . Furthermore, transfer of an electron from the σ(C−H) of C 3 H 8 to another antibonding orbital of 3 O 2 , leading to the generation of C 3 H 7 radical. C 2 H 4 formation over the B−B site has the lowest barrier, arising from the least strained seven‐membered ring and the simultaneous cleavage of σ(C−C) and σ(C−O) bonds. This study underscores the industrial potential of boron‐based catalysts.