Reactant-dependent volcano trends in Pt-catalyzed cycloalkane dehydrogenation: orbital hybridization-guided design of active sites.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41365866.
- Also identified by DOI 10.1038/s41467-025-66782-w and PMC identifier 12770571.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Catalyst design is often reaction-specific due to the lack of universal descriptors linking molecular structures to optimal active-site configurations. Here, we uncover a reactant-dependent volcano relationship in Pt-catalyzed dehydrogenation, governed by the Pt-Pt coordination number (CN<sub>Pt-Pt</sub>). Using a tunable Pt/MgAl<sub>2</sub>O<sub>4</sub> system, we identify optimal CN<sub>Pt-Pt</sub> values of ~2.5, ~4.7, and ~7.0 for cyclohexane, methylcyclohexane, and decalin, respectively. This activity trend is explained by an orbital hybridization-guided mechanism, where optimal activity emerges from a balance between C-H bond activation and product desorption, mediated by the interactions between Pt d-orbitals and the π* orbitals of dehydrogenated intermediates. We introduce the LUMO energy of aromatic products as a universal electronic descriptor that serves as a proxy for π* orbital energy. LUMO energy shows strong linear correlations with the d-band center of Pt at the optimal CN<sub>Pt-Pt</sub>, enabling rational tuning of electronic interactions across diverse reactants. The optimized Pt/MgAl<sub>2</sub>O<sub>4</sub> catalyst delivers 2-3 times higher activity with >100 h stability under industrial conditions at only 300 <sup>o</sup>C, offering a robust strategy for hydrogen release and active-site engineering in dehydrogenation catalysis.