In Situ Chalcogen Leaching Manipulates Reactant Interface toward Efficient Amine Electrooxidation

Engineering the reaction interface is necessary for advancing various electrocatalytic processes. However, most designed catalysts tend to be ineffective due to the inevitable structural reconstruction. Here we utilize that operando electrocatalysis variations (i.e., chalcogen leaching) manipulate the reactant interface toward amine electrooxidation. Taking chalcogen-doped Ni(OH)(2) as an example, operando techniques uncover that chalcogens leach from the matrix and then adsorb on the surface of NiOOH as chalcogenates during the electrooxidation process. The charged chalcogenates will induce the local electric field that pushes the polar amines through the inner Helmholtz plane to enrich on the catalyst surface. Meanwhile, the polarization effect of chalcogenates and amines boost amino C-N bond activation for dehydrogenation into nitrile C N bonds. Under the promotion effect of surface-adsorbed chalcogenate ions, our catalysts display over 99.5% propionitrile selectivity at the low potential of 1.317 V with an ultrahigh current density. This finding highlights the use of operando changes of catalysts to rationally design efficient catalysts and further clarifies the underlying role of chalcogen atoms in the electrooxidation process.

Automated summary

Engineering the reaction interface is crucial for advancing electrocatalytic processes. This study demonstrates that operando electrocatalysis variations can manipulate the reactant interface to improve amine electrooxidation. Experimental evidence reveals that chalcogen elements leach from the matrix and adsorb on the catalyst surface, enhancing the reaction efficiency. This finding provides important insights for the rational design of efficient catalysts.