Enhancing C─C Bond Cleavage of Glycerol Electrooxidation Through Spin‐Selective Electron Donation in Pd–PdS ₂ –Co _x Heterostructural Nanosheets

Abstract

Abstract As a 4 d transition metal, the spin state of Pd is extremely difficult to directly regulate for the optimized d orbital states owing to the strong spin‐orbit coupling effect and further extended d orbital. Herein, we devise a “spin‐selective electron donation” strategy to tune specific d orbital electrons of Pd inspired by the Dewar−Chatt−Duncanson model theory. Co−S−Pd bridges with different spin‐states of Co III have been constructed in a series of Pd–PdS 2 –Co x HNSs with tunable Co content. Experiments and theoretical calculations indicate that low‐spin Co III (t 2g 6 e g 0 ) with fully occupied t 2g orbitals and empty orbitals can accurately alter the electron of Pd by σ‐donation via the Co−S−Pd bridge. In contrast, the unfilled d xy orbital of high‐spin Co III (t 2g 5 e g 1 ) is essential for controlling the d xy electron of Pd via π‐donation. Benefiting from state optimization by σ‐donation, Pd–PdS 2 –Co 4.0 delivers superior performance toward various bio‐alcohols (ethanol, ethylene glycol, and glycerol) with enhanced C─C bond cleavage. Furthermore, coupling the glycerol oxidation reaction with the CO 2 reduction reaction (GOR||CO 2 RR), the electricity consumption of GOR||CO 2 RR drops 46.4% compared to the state‐of‐art system (OER||CO 2 RR). Moreover, anodic Faraday efficiency (FE) of formic acid can be attainable at more than 90% at low voltage regions.