▎ 摘　　要

Sensitive and selective detection of methane (CH4) is crucial for human activities, but is severely challenging due its volatility and nonpolar nature. Herein, with the aid of first-principles calculations, we explore the potential of single transition metal atoms (Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt and Au) embedded in graphene with four pyridine nitrogen atoms doped (TMN4 @G) as efficient sensor materials towards CH4. It is found that AgN4 @G enables outstanding sensitivity, selectivity and recovery ability for CH4 detection in ambient condition. Further calculations in the presence of O-2 or H2O revealed that the sensitivity of the system is remarkably improved, indicating its applicability and robustness for CH4 sensing in ambient or humid conditions.