Trimetallic Oxide Electrocatalyst for Enhanced Redox Activity in Zinc–Air Batteries Evaluated by In Situ Analysis

Abstract

Researchers are investigating innovative composite materials for renewable energy and energy storage systems. The major goals of this studies are i) to develop a low‐cost and stable trimetallic oxide catalyst and ii) to change the electrical environment of the active sites through site‐selective Mo substitution. The effect of Mo on NiCoMoO4 is elucidated using both in situ X‐ray absorption spectroscopy and X‐ray diffraction analysis. Also, density functional theory strategies show that NiCoMoO4 has extraordinary catalytic redox activity because of the high adsorption energy of the Mo atom on the active crystal plane. Further, it is demonstrated that hierarchical nanoflower structures of NiCoMoO4 on reduced graphene oxide can be employed as a powerful bifunctional electrocatalyst for oxygen reduction/evolution reactions in alkaline solutions, providing a small overpotential difference of 0.75 V. Also, Zn–air batteries based on the developed bifunctional electrocatalyst exhibit outstanding cycling stability and a high‐power density of 125.1 mW cm−2. This work encourages the use of Zn–air batteries in practical applications and provides an interesting concept for designing a bifunctional electrocatalyst.

Durable Electrocatalyst Support Materials Based on N-Doped Mesoporous Carbon Nanofibers with Titanium Nitride Overlay Coating for High-Performance Proton Exchange Membrane Fuel Cells

“…These results are in good agreement with the CV and LSV observations and additionally confirm that Pt/TiN/ g -C 3 N 4 / m -PCNFs have more abundant Pt active sites, improved electrolyte diffusion, and faster interfacial charge transfer and consequently enhancing the ORR kinetics. Moreover, there are two assumptions can be made on the remarkable performance of Pt/TiN/ g -C 3 N 4 / m -PCNFs toward ORR: (i) owing to their porous structure, the m -PCNFs have a superior charge transfer rate, improved mass transport and gas diffusion, and greater interfacial interaction with the electrolyte than the Pt nanoparticles , ; (ii) the amorphous TiN acts as a protective layer on the m -PCNFs, which can greatly enhance corrosion resistance, while the g -C 3 N 4 offering high electrical conductivity.…”

“…4 /m-PCNFs toward ORR: (i) owing to their porous structure, the m-PCNFs have a superior charge transfer rate, improved mass transport and gas diffusion, and greater interfacial interaction with the electrolyte than the Pt nanoparticles59,60 ; (ii) the amorphous TiN acts as a protective https://doi.org/10.1021/acsanm.3c03997 ACS Appl. Nano Mater.…”

Two dimensional oxides for oxygen evolution reactions and related device applications

“…9d–h). Kumar et al 134 developed a low-cost and stable trimetallic oxide catalyst NiCoMoO 4 @rGO via a one-step hydrothermal method, where changes in the electrical environment of the active sites were modified via site-selective Mo substitution. Operando XAS, in situ XRD and DFT analyses revealed the crucial role of Mo atoms in reducing the overpotential and optimizing the energy barriers.…”

Mo-Doped Na4Fe3(PO4)2P2O7/C Composites for High-Rate and Long-Life Sodium-Ion Batteries

“…For example, Wen et al [28] enhanced the Li + diffusion rate in LiMn 0.6 Fe 0.4 PO 4 materials by doping with Mo 6+ , achieving discharge capacities of 153.2 mAh g −1 at 0.2 C and 94.2 mAh g −1 at 10 C, with a capacity retention rate of 91.4% after 100 cycles at 1 C. For polyanionic cathode materials, the performance enhancement achieved by Mo 6+ doping is not only attributed to the strong Mo-O bond energy (502 kJ/mol) [29], which can increase the structural stability, but also to the decrease in charge transfer impedance and the generation of vacancies, which enhance the ion/electron transport, thereby accelerating the ion transport rates [21,24,26]. Additionally, Kumar et al demonstrated that Mo doping in trimetallic oxides significantly enhances the redox activity by optimizing the energy barriers in the reaction steps and increasing the adsorption energy of intermediates, thereby improving the overall performance in zinc-air batteries [30]. However, studies on Mo 6+ doping in NFPP have not yet been reported.…”