Highly efficient bifunctional catalyst with 2D MoN formed in situ synergy for OER and ORR based-on Co(II) doped Mo(IV)-Ni(II) supramolecular coordination polymer

Developing non-precious metal oxygen electrocatalysts is of great significance for storage systems and energy conversion. Pyrolyzation of the bimetallic Mo(IV)-Ni(II) supramolecular coordination polymer (SCP) for the first time by simultaneously introducing Co(II) ion with Graphene Oxide (GO) as template leads to a new outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional electrocatalyst (GO-Co@MoNi) composed structurally by 2D MoN flake formed in situ and CoNi alloy supported on lamellar GO. The unique components, sheet architecture, and intermetallic synergy of the GO-Co@MoNi catalyst (eta = 340 mV, E-1/2 = 0.855V) endow it comparable electrocatalytic performance towards OER to the commercial RuO2 electro-catalysts (eta = 320 mV) and superior performance towards ORR to Pt/C (E-1/2 = 0.84 V) electrocatalyst. Density functional theory (DFT) calculation reveals the essential role of trimetallic synergy at an unprecedented comfortable 4 x 1e(-) electrons reaction pathway in the excellent ORR in GO-Co@MoNi. The current research opens a skillful design strategy and a rare catalytic mechanism for constructing new oxygen electrocatalysts, and the results show that the SCP-based materials have great potential in the electrochemical field in the future, especially for efficient bifunctional electrocatalysts.

Automated summary

Developing non-precious metal oxygen electrocatalysts is significant for storage systems and energy conversion. This study successfully synthesized an outstanding bifunctional electrocatalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) by pyrolyzing a bimetallic supramolecular coordination polymer (SCP) with the introduction of Co(II) ion and graphene oxide (GO) as a template. The newly developed catalyst exhibited comparable OER performance to commercial RuO2 catalysts and superior ORR performance to Pt/C catalysts.