Competitive Coordination Constructed Heteronuclear Pt₁-Fe₁ Dual Single-Atom Sites for Selective Oxidation of Allylic...

Dual single-atom catalysts (DSACs) have attracted considerable attention owing to their exceptional atom efficiency and synergistic catalytic effects. Nevertheless, establishing precise synthetic methodologies for DSACs and exploring its application in complex reaction systems still present significant challenges. Here, we have fabricated a hydroxyapatite (HAP)-supported heteronuclear Pt₁-Fe₁ dual single-atom catalyst (Pt₁-Fe₁/HAP) via a competitive coordination strategy for selective oxidation of allylic alcohols. Through a thermodynamically driven competitive coordination process, heteronuclear Pt₁-Fe₁ with distinct charge densities is co-anchored within adjacent periodic Ca²⁺ vacancies of HAP lattice via PO₄ ^3- bridges, achieving a controlled atomic separation of ∼2.7 Å for electronic synergy. Unexpectedly, orbital hybridization between heteronuclear Pt₁-Fe₁ induces a spin-state transition of Fe from low-spin to medium-spin, facilitating activation of O₂ and following cascade oxidation of allylic alcohol. Benefiting from the modification of spin state, Pt₁-Fe₁/HAP exhibits ultrahigh aldehyde selectivity (92%) and a high turnover frequency (12 090.8 h^-1) in oxidation of various allylic alcohol substrates, 20-fold higher than that of Pt₁/HAP single-atom catalyst (543.8 h^-1). This work establishes the thermodynamically driven competitive coordination strategy as a universal approach for constructing high-performance heteronuclear dual-atom catalysts with precisely engineered electronic synergy in demanding industrial processes.