E_b-TM^x+ (eV)

E_ads-HCOOH (eV)

C₂N→TM^x+ charge (e−)

HCOOH→C2N-TM^x+ charge (e−)

C₂N-Co²⁺

15.16

0.83

−1.11

−0.07

C₂N-Cu²⁺

16.14

0.48

−1.12

−0.02

C₂N-Ni²⁺

14.64

1.15

−1.08

0.01