Investigate the role of V in the Nitrogen-doped hierarchical porous carbon-supported binary transition metal nitrides catalyst for oxygen reduction reactions

N-doped carbon-supported titanium nitride (TiN/NC) is considered promising for its application in Zn-air batteries. However, the performance of TiN/NC cannot meet the practical application. To solve this problem, the catalytic activity and stability of the catalyst can be improved by introducing the second metal element V. In this paper, a high-performance catalyst (TixV1−xN/NC/C) was prepared by supporting titanium-vanadium binary transition metal nitride nanoparticles on nitrogen-doped carbon. The experimental results and density functional theory (DFT) calculations confirm that the electronic, atomic and microstructure of titanium nitride nanoparticles can be properly tuned by introducing V ions, which is beneficial to tune the adsorption/adsorption of oxygen intermediates on titanium nitride nanoparticles and decreasing the potential of the rate determining step, thereby increasing the catalytic activity. The TixV1−xN/NC/C composite exhibits excellent ORR performance with an onset potential (Eonset) and limiting current density of 0.91 V (vs. RHE) and 4.90 mA∙cm−2, respectively. The Ti0.85V0.15N/NC/C-based Zn-air battery exhibits the power density of 124.78 mW·cm−2, open circuit voltage of 1.34 V and high specific capacity of 731.38 mAh·g−1. More importantly, this work has deepened the understanding of the TMN-based catalytic mechanism and paved the way for enhancing the catalytic performance of TMN-based catalysts. [Display omitted] •DCDA instead of NH3 was used skillfully to fabricate a novel high-performance TixV1-xN/NC composite materials.•The TixV1-xN/NC composite exhibits positive half-wave potential, high limiting current density, and excellent durability.•The Ti0.85V0.15N/NC-based Zn-air battery exhibits the highest power density and high specific capacity.•DFT calculations show that the adsorption/desorption of ORR intermediates can be optimized by introducing V ions.