Fig. 3
From: Selectively nitrogen-doped carbon materials as superior metal-free catalysts for oxygen reduction
Reaction equations and enthalpy changes. a A reaction equation and enthalpy changes for substituting C in graphene with N. b A reaction equation and enthalpy change for substituting C linked to a acetylenic bond in hydrogen-substituted graphdiyne (HsGDY) with graphitic N. c A reaction equation and enthalpy change for substituting C on the inside of HsGDY with pyridinic N. d A reaction equation and enthalpy change for substituting C at the edge of HsGDY with pyridinic N. The C in the benzene ring at the edge of HsGDY was linked with H (d)
