The influence of ruthenium substitution in LaCoO₃ towards bi-functional electrocatalytic activity for rechargeable Zn–air batteries

Abstract

The rechargeable Zinc-air battery is a clean technology for energy storage applications but is impeded by the slow kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER)...

Co/MoC Nanoparticles Embedded in Carbon Nanoboxes as Robust Trifunctional Electrocatalysts for a Zn–Air Battery and Water Electrocatalysis

“…The charge-transfer resistance could be measured by the electrochemical impedance spectroscopy (EIS). Nyquist plots shown in Figure d reveal the smallest diameter of the semicircles for the Co@IC/MoC@PC catalyst, indicating its best charge-transfer behavior for ORR. , Next, to investigate the origins of the fast kinetics and striking ORR catalytic activity of Co@IC/MoC@PC, ultraviolet photoelectron spectroscopy was employed to evaluate the electron-donating abilities of the samples. As obviously seen in Figure , the Co@IC/MoC@PC catalyst shows an expected valence band maximum value of 0.13 eV, close to the Fermi level ( E F , set to 0 eV) and lower than 0.19 eV of Co@IC, implying that the exposed surfaces of Co@IC/MoC@PC nanocomposites possess more metallic character with higher density of states around E F . − Not surprisingly, the calculated working function of the Co@IC/MoC@PC is expected to be 4.19 eV, smaller than that of Co@IC catalyst.…”

Regulating the Interfacial Electron Density of La0.8Sr0.2Mn0.5Co0.5O3/RuOx for Efficient and Low-Cost Bifunctional Oxygen Electrocatalysts and Rechargeable Zn-Air Batteries

“…Although the peak area power density (Figure b) of LSMC-Ru (159 mW cm –2 ) is lower than that of Pt/C + RuO 2 (206 mW cm –2 ), it is competitive to recently reported perovskite-based and Ru-based analogues (Table S3). ,,,,− In addition, the discharge profiles of the ZAB at different current densities from 1 to 30 mA cm –2 (Figure c) show the good rate capability and fast dynamic response upon the current setting up and down, implying the potential application in automobiles . The cycle stability of the ZAB is tested at 2 mA cm –2 (Figure d).…”

“…For example, noble metal Ir was introduced into the B-site of the perovskite structure by doping to form SrIrO 3 and SrZr x Ir 1– x O 3 , which achieved higher OER activity (overpotential of 240 mV at a current density of 10 mA cm –2 ) with lower Ir content (40 wt %) than the benchmark IrO 2 . Similarly, a Ru-doped LaCoO 3 perovskite was synthesized and applied as the electrocatalysts for ZABs, which delivered decent bifunctional OER/ORR activity and battery performance . However, ball milling and doping may cause the noble metals to distribute throughout the entire bulk material, and thus the exposure and utilization of noble metals are both low, leading to the high dosage of the noble metals (i.e., 33–58 wt %) ,, and thus the high cost.…”

“…13 Similarly, a Ru-doped LaCoO 3 perovskite was synthesized and applied as the electrocatalysts for ZABs, which delivered decent bifunctional OER/ORR activity and battery performance. 14 However, ball milling and doping may cause the noble metals to distribute throughout the entire bulk material, and thus the exposure and utilization of noble metals are both low, leading to the high dosage of the noble metals (i.e., 33−58 wt %) 12,13,15 and thus the high cost. For comparison, surface anchoring could be a better method to load low-dosage noble metals on the surface of non-noble metals.…”

One-step synthesis of CeFeO3 nanoparticles on porous nanocarbon frameworks derived from ZIF-8 for a boosted oxygen reduction reaction in pH universal electrolytes

“…5,6 A broad range of non-precious-metal electrocatalysts with prospective activity in the ORR process have been reported, including nanocarbon materials, 7 alloys, 8,9 ABO 3 perovskite oxides, [10][11][12][13] transitionmetal oxides, 14 carbides, 15 nitrides, 16 and suldes. 17,18 Among these promising catalysts, ABO 3 perovskite oxides, where A is a rare earth metal or alkaline earth element and B is a transition metal element (TM ¼ Co, Ni, Mn, Fe), 19 have become promising alternatives for noble-metal-based catalysts due to their abundant reserves and low cost. 20 In particular, the B-sites of ABO 3 perovskite oxides, which are generally considered as active sites due to the mixed valence states of the transition metals, are favorable for oxygen activation.…”