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Transient Overcoordination Unlocks C-H Bond Activation in Boron-Based Oxidative Dehydrogenation
Leyuan Cui1, Dandan Song1, Ruixuan Qin1,2
1State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Journal of the American Chemical Society
|July 9, 2026
Summary
The active site in boron-catalyzed oxidative dehydrogenation of propane (ODHP) is not static but involves dynamic, transiently overcoordinated [BO4] species. This coordination-fluxionality mechanism explains efficient C-H activation and high propylene selectivity.
Area of Science:
- Heterogeneous Catalysis
- Materials Science
- Computational Chemistry
Background:
- The active site in boron-catalyzed oxidative dehydrogenation of propane (ODHP) is poorly understood, with existing models failing to explain how B(III) mediates C-H activation and maintains selectivity.
- Prevailing theories propose static, high-energy boron oxide (BOx) species, which do not resolve the paradox of efficient catalysis by a nonreducible boron center.
Purpose of the Study:
- To identify the true active site and elucidate the mechanism behind boron-catalyzed ODHP.
- To resolve the paradox of C-H activation and high propylene selectivity mediated by a B(III) center.
Main Methods:
- Exhaustive thermodynamic screening of 9700 BOx/Ni(111) configurations.
- Enhanced sampling ab initio molecular dynamics (AIMD) simulations.
- Free-energy barrier calculations across various doped and metal-free BOx systems.
Main Results:
- Catalytic activity is driven by transiently accessible, overcoordinated [BO4] species formed via dynamic [BO3] ⇌ [BO4] interconversions, not pre-existing structures.
- Dynamic sp2-to-sp3 rehybridization in boron centers acts as an electronic buffer, enabling C-H activation without localized reduction of B(III).
- Structurally adaptive boron centers preferentially adsorb oxygenated radicals, suppressing chain propagation and preventing deep oxidation to COx, thus explaining high propylene selectivity.
Conclusions:
- The mechanism of boron catalysis in ODHP relies on coordination-fluxionality, where transient coordination states are key.
- Catalyst design should focus on engineering the accessibility and lifetime of these transient states rather than seeking a single static active site.
- This dynamic mechanism is general across various BOx systems, including doped and metal-free variants.
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