Na2MnP2O7 polymorphs as efficient bifunctional catalysts for oxygen reduction and oxygen evolution reactions.

In order to design earth-abundant low cost electrocatalysts, this communication exploits polymorphism in Na2MnP2O7 pyrophosphate sodium insertion materials. Two polymorphs of Na2MnP2O7 have been prepared with a short annealing duration of 30 minutes. These scalable materials exhibit efficient bifunctional electrocatalytic activity stemming from the Mn redox centre and robust structural framework.