Solid-State Ball-Milling of Co3O4 Nano/Microspheres and Carbon Black Endorsed LaMnO3 Perovskite Catalyst for Bifunctional Oxygen Electrocatalysis

Abstract

Developing a highly stable and non-precious, low-cost, bifunctional electrocatalyst is essential for energy storage and energy conversion devices due to the increasing demand from the consumers. Therefore, the fabrication of a bifunctional electrocatalyst is an emerging focus for the promotion and dissemination of energy storage/conversion devices. Spinel and perovskite transition metal oxides have been widely explored as efficient bifunctional electrocatalysts to replace the noble metals in fuel cell and metal-air batteries. In this work, we developed a bifunctional catalyst for oxygen reduction and oxygen evolution reaction (ORR/OER) study using the mechanochemical route coupling of cobalt oxide nano/microspheres and carbon black particles incorporated lanthanum manganite perovskite (LaMnO3@C-Co3O4) composite. It was synthesized through a simple and less-time consuming solid-state ball-milling method. The synthesized LaMnO3@C-Co3O4 composite was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction spectroscopy, and micro-Raman spectroscopy techniques. The electrocatalysis results showed excellent electrochemical activity towards ORR/OER kinetics using LaMnO3@C-Co3O4 catalyst, as compared with Pt/C, bare LaMnO3@C, and LaMnO3@C-RuO2 catalysts. The observed results suggested that the newly developed LaMnO3@C-Co3O4 electrocatalyst can be used as a potential candidate for air-cathodes in fuel cell and metal-air batteries.

An In Situ Temperature-Dependent Study of La2O3 Reactivation Process

“…The rare earth lanthanum is contained in a wide and important class of oxidation catalysts and electrocatalysts such as perovskites and MOF (Alcalde-Santiago et al, 2020;Lee, 2020;Karuppiah et al, 2021). These materials can be used as deep oxidation catalysts for a wide range of environmental applications (Hu et al, 2021;Ishisone et al, 2021;Le et al, 2021), which include membrane materials, electrocatalytic materials (Brugge et al, 2020), and materials in solid oxide fuel cells (SOFCs) (Duan et al, 2020).…”

Graphene Nanosheet-Wrapped Mesoporous La0.8Ce0.2Fe0.5Mn0.5O3 Perovskite Oxide Composite for Improved Oxygen Reaction Electro-Kinetics and Li-O2 Battery Application

“…Typical ORR curves were observed from CV scans (20 mV s −1 ) for all the catalyst-modified electrodes, such as 20 wt.% of Pt/C, GNS, LCFM(8255)-gly, LCFM(5555)-gly/GNS and LCFM(8255)-gly/GNS composite catalysts (Figure 5A). The ORR peak potential (at −0.35 V vs. Ag/AgCl) of LCFM(8255)-gly perovskite is far better than the previously published undoped LaMnO 3 perovskite catalyst (at −0.48 V vs. Ag/AgCl) [29]. However, the peak potential of the composite electrodes, i.e., LCFM(5555)gly/GNS and LCFM(8255)-gly/GNS, was significantly improved, nearly to commercial Pt/C electrode activity, which is due to the high electrical conductivity of GNS.…”

“…On the other hand, the pore size of LCFM(8255)-gly is reduced to 6.3 nm, and the pore volume is increased to approximately 0.071 m 3 g −1 , which confirms the residue of CeO 2 nanoparticles may be positioned onto the pores of the LCFM(8255)-gly microsphere particles (Figure 2F). The obtained specific surface area (38.38 m 2 g −1 ) of LCFM(8255)-gly perovskite is much higher than the previously reported LaMnO 3 perovskites [16,[23][24][25]29]. Thus, the existence of a large number of pores in LCFM(8255)-gly microspheres can provide support for the efficient diffusion of electrolyte ions and O 2 gas in both O 2 electrocatalysis and Li-O 2 battery performance.…”

Dielectric and electrochemical performance of rhombohedral lanthanum manganite perovskite nanostructures

“…The La 3d 5/2 doublet splitting having a separation value of 3.5 eV exposes the presence of lanthanum hydroxides. 41 The spectra of Mn 2p exhibit a doublet at 642 and 653.5 eV corresponding to Mn 2p 3/2 and Mn 2p 1/2 , respectively. The Mn 2p 3/2 peak has two deconvoluted peaks at 641.6 eV and 643.3 eV which can be assigned to the Mn 3+ and Mn 4+ valence states (Fig.…”