Noble metal single-atom catalyst supported by C[formula omitted]N[formula omitted] monolayer as a promising reduction electrocatalyst for low-density environmental NO

Abstract

Here, we show that the noble metal atoms decorated over the porous monolayer of C8N8 demonstrate superior performance in the reduction reaction of low-density environmental NO gas. Among different considered single-atom catalysts (SAC), the osmium atom exhibits the most energetically favored NO-reduction pathway with the free energy change of −12.71 eV even at low NO coverage. Both nitrogen- and carbon-dominated large rings are capable of adsorbing NM atoms to form NM@C8N8 configurations. Fortunately, no clustering resulted for the noble metal atoms anchored onto the pristine C8N8 due to the substantial binding energy of −12.87 eV. The considered SACs exhibit their electrocatalytic activities by the dominant contribution to the total DOS around the Fermi level, especially for the Os, Ir, and Rh adatoms. At low NO coverage, NOER over Os@C8N8 proceeds the downhill profile diagram and demonstrates promising electrocatalytic performance in NO-reduction. Similarly, at high NO coverage, N2O2 can be adsorbed by NM@C8N8, due to the negative value of the free energy change.