A Bifunctional Hybrid Electrocatalyst for Oxygen Reduction and Oxygen Evolution Reactions: Nano-Co3O4-Deposited La0.5Sr0.5MnO3 via Infiltration

Abstract

For rechargeable metal–air batteries, which are a promising energy storage device for renewable and sustainable energy technologies, the development of cost-effective electrocatalysts with effective bifunctional activity for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) has been a challenging task. To realize highly effective ORR and OER electrocatalysts, we present a hybrid catalyst, Co3O4-infiltrated La0.5Sr0.5MnO3-δ (LSM@Co3O4), synthesized using an electrospray and infiltration technique. This study expands the scope of the infiltration technique by depositing ~18 nm nanoparticles on unprecedented ~70 nm nano-scaffolds. The hybrid LSM@Co3O4 catalyst exhibits high catalytic activities for both ORR and OER (~7 times, ~1.5 times, and ~1.6 times higher than LSM, Co3O4, and IrO2, respectively) in terms of onset potential and limiting current density. Moreover, with the LSM@Co3O4, the number of electrons transferred reaches four, indicating that the catalyst is effective in the reduction reaction of O2 via a direct four-electron pathway. The study demonstrates that hybrid catalysts are a promising approach for oxygen electrocatalysts for renewable and sustainable energy devices.

Transition Metal‐based Perovskite Oxides: Emerging Electrocatalysts for Oxygen Evolution Reaction

“…It is observed that composite material formed by physical mixing often leads to weak interfacial interaction between perovskite and composite elements which results in limited activity and stability; thus, methods such as electrospinning, electrospray pyrolysis, chemical vapor deposition, and hydrothermal methods are adopted to homogeneously and uniformly disperse/encapsulate perovskite material in composite elements. Kim et al ., form hybrid catalyst of Co 3 O 4 ‐infiltrated La 0.5 Sr 0.5 MnO 3‐δ with electrospray and infiltration techniques [132] . Because the incorporation of carbon can nullify the issues of low conductivity and surface area, Thomas and co‐authors formed LaFe 0.8 Co 0.2 O 3 /carbon hybrid materials by adopting a solution combustion method followed by calcination.…”

“…Kim et al ., utilized electrospray and infiltration techniques to deposit Co 3 O 4 nanoparticles on the surface of La 0.5 Sr 0.5 MnO 3‐δ nano‐scaffold and interpreted that La 0.5 Sr 0.5 MnO 3‐δ @ Co 3 O 4 displayed OER 7, 1.5,and 1.6 times better response than La 0.5 Sr 0.5 MnO 3‐δ , Co 3 O 4 , and IrO 2 , respectively. It was observed that due to the difference in the electronic configuration of La 0.5 Sr 0.5 MnO 3‐δ and Co 3 O 4 , there is an increase in the concentration of Co 3+ ions and electron‐rich phases in the heterostructure, which is responsible for the improved performance [132] . Khan et al ., formed a 3D heterostructure of La 0.4 Sr 0.4 Ti 0.9 Ni 0.1 O 3‐δ @NiMn‐LDH supported on Ni foam.…”

“…It was observed that due to the difference in the electronic configuration of La 0.5 Sr 0.5 MnO 3-δ and Co 3 O 4 , there is an increase in the concentration of Co 3 + ions and electron-rich phases in the heterostructure, which is responsible for the improved performance. [132] Khan et al, formed a 3D heterostructure of La 0.4 Sr 0.4 Ti 0.9 Ni 0.1 O 3-δ @NiMn-LDH supported on Ni foam. This heterostructure displayed outstanding performance due to the synergistic effect introduced by the hybrid catalyst.…”

In Honor of John Bannister Goodenough, an Outstanding Visionary

“…This study presents new very-high-resolution electron microcopy techniques. (8) This contribution by Seona Kim, Guntae Kim and Arumugam Manthiram [14] is concerned with rechargeable metal-air batteries. As an example of cost-effective electrocatalysts with effective bifunctional activity for both oxygen reduction and oxygen evolution, they discussed a hybrid catalyst, Co 3 O 4 -infiltrated La 0.5 Sr 0.5 MnO 3-δ , to demonstrate that hybrid catalysts are a promising approach for oxygen electrocatalysts for renewable and sustainable energy devices.…”

Synergistic Catalysis of SnO2/Reduced Graphene Oxide for VO2+/VO2+ and V2+/V3+ Redox Reactions

“…In order to solve this problem and achieve “carbon neutrality”, humankind began to explore renewable energy [ 5 , 6 , 7 , 8 , 9 ]. However, this type of energy is not always available at all times, and in most cases, due to the oscillation of energy availability in its cycle and peak demand, supply and demand are not synchronized [ 10 , 11 , 12 , 13 , 14 , 15 ]. Energy storage equipment is needed to store and transform the electric energy generated by renewable energy sources to realize its large-scale application [ 16 , 17 , 18 , 19 , 20 ].…”