Table 2.

Binding energies (BE) of Cu₂–N₆/Gr, Cu₂–N₈/Gr, Cu–N₄/Gr structures with and without solvent energies (SE) [34] and shortest distance (d) between Cu–O, O–O atoms in angstroms (Å). The Mulliken charge of the adsorbate (Q_x) and the Mulliken charge of the Cu site (Q_Cu) for the shortest distance of the optimized structure. (01) and (02) in the Cu₂–N₆/Gr defect represent the different ORR paths 03-04-06-08 and 01-05-08 in Fig. 1, respectively. Two Mulliken charge values represent the atom order of the molecule column. Here, e = 1.602 × 10⁻¹⁹ C.

Defect	Molecule	BE (without solvent)/eV	SE/eV	BE (with solvent)/eV	dO-O/Å	dCU-O/Å	Qx/e	QCu/e
CU2–N6/GR (01)	O + O	−3.54	−0.41	−3.95	1.50	1.82	−0.223, −0.365	0.979
	OOH	−4.13	−0.47	−4.60	1.55	1.84	−0.328	0.934
	O	−7.53	−0.70	−8.23	–	1.74	−0.592	1.087
	OH	−5.12	−0.38	−5.50	–	1.89	−0.643	0.952
	H2O	−1.30	–	–	–	2.09	−0.573	0.937
	OH + OH (H2O2)	−5.44	–	–	2.48	1.75,1.85	−0.618, −0.602	0.947, 0.744
CU2–N6/GR (02)	O + O	−3.78	−0.41	−4.19	1.49	1.82	−0.367, −0.220	1.010
	O + OH	−9.52	−1.08	−10.60	2.52	1.83	−0.368, −0.661	0.631, 1.051
	OH + OH	−6.52	−0.76	−7.28	2.45	1.79	−0.665, −0.605	1.060, 0.897
	OH	−5.13	−0.38	−5.51	–	1.89	−0.640	0.949
	H2O	−1.30	–	–	–	2.09	−0.573	0.937
CU2–N8/GR	O2	−2.79	−0.41	−3.20	1.46	1.89	−0.273	0.967
	OOH	−3.27	−0.47	−3.74	1.55	1.93	−0.303	0.993
	OH + OH	−5.34	−0.76	−6.10	2.66	1.81,1.86	−0.606, −0.612	0.919,0.845
	OH	−3.81	−0.38	−4.19	–	2.05	−0.615	1.015
	H2O	−0.98	–	–	–	2.20	−0.599	1.068
CU-N4/GR	O2	−2.76	−0.41	−3.17	1.38	1.98	−0.195	0.996
	OOH	−1.70	−0.47	−2.17	1.52	1.87	−0.312	0.922
	O	−5.15	−0.70	−5.85	–	1.88	−0.312	0.905
	OH	−1.99	−0.38	–	–	1.84	−0.581	0.857
	H2O	−1.23	–	–	–	2.08	−0.587	1.011
	H2O2	−0.92	–	–	1.54	2.18	−0.319	0.999