Investigation of a Single Atom Iron Catalyst for the\nElectrocatalytic Reduction of Nitric Oxide to Hydroxylamine: A DFT\nStudy

Hydroxylamine,\nas an important reducing agent, disinfectant, foaming\nagent, and biocide, plays a role in both human life and industrial\nproduction. However, its synthesis is confronted with challenges,\nsuch as high pollution and large consumption. Here, we propose a coordination\ntailoring strategy to design 47 graphene-supported single iron atom\ncatalysts (SACs), namely, Fe@C<sub><i>x</i></sub>Z<sub><i>y</i></sub> (Z = B, N, O, P, and S), for the reduction of nitric\noxide to hydroxylamine. Using density functional theory calculations,\nwe demonstrated the great impact of the coordination environment on\nthe stability, catalytic selectivity, and activity of the Fe site.\nWe identified that the experimentally available Fe@N<sub>4</sub> possesses\nan ultralow theoretical limiting potential of −0.32 V compared\nto that of other catalysts. A comprehensive investigation of the electronic\nproperties elucidates the underlying active origin and reaction mechanism\nof the nitric oxide reduction reaction to hydroxylamine on Fe@N<sub>4</sub>. These results not only explain the catalytic origin of synthesized\nSACs for the NH<sub>2</sub>OH production but also offer theoretical\nguidance for further optimizing high-performance catalysts.