Yolk‐Shell Structured Zinc‐Cobalt‐Ruthenium Alloy Oxide Assembled with Ultra‐Small Nanoparticles: A Superior Cascade Catalyst toward Oxygen Evolution Reaction

Abstract

Structure engineering has proven to be an effective strategy for improving the catalytic performance and reducing the cost of ruthenium oxide‐based catalysts toward oxygen evolution reactions (OER). Herein, a polyhedron‐shaped yolk‐shell structure composed of zinc‐cobalt‐ruthenium ternary metal alloy oxide (ZnCo‐RuO2/C) is prepared, by taking advantage of the Kirkendall effect. The yolk‐shell frame and the ensembled metal oxide nanoparticles are 116.9 ± 25.9 nm and 3.1 ± 0.7 nm in diameter, respectively. The porous yolk‐shell structure of ZnCo‐RuO2/C exposes abundant active sites and facilitates mass transfer for OER. Theoretical calculations indicate that ZnCo‐RuO2 may break the linear scaling relationship for the OER intermediates and dramatically reduces the energy barrier of the potential determining step, which may be one of the factors that are responsible for the enhanced OER performance of ZnCo‐RuO2/C. In 1 m KOH aqueous electrolyte, ZnCo‐RuO2/C delivers an overpotential of only 180 mV at 10 mA cm−2 and a Tafel slope of 63 mV dec−1, superior to that of single metal‐doped, pristine and commercial RuO2. As an anode catalyst of zinc‐air batteries, ZnCo‐RuO2/C exhibits improved power density and durability relative to commercial RuO2, very promising for practical application.

MOF-Derived Fe2CoSe4@NC and Fe2NiSe4@NC Composite Anode Materials towards High-Performance Na-Ion Storage

“…[29,30]. The Co 2p of Fe2CoSe4@NC (Figure 3b) exhibits peaks at 780.3 and 796.3 eV, which are attributed to the Co 2+ 2p3/2 and 2p1/2 orbitals, accompanied with two satellite peaks at 785.9 and 802.8 eV, respectively [31][32][33][34][35]. As depicted in Figure 3e, the high-resolution XPS spectrum of Ni 2+ 2p comprises a pair of spin-orbit doublets at 854.6 and 873.2 eV, as well as two satellite peaks [36,37].…”

RuO2 Catalysts for Electrocatalytic Oxygen Evolution in Acidic Media: Mechanism, Activity Promotion Strategy and Research Progress

“…The utilization efficiency of the active site can be significantly increased by the large surface area of the carrier carrying the active site. In addition, the coupling of metal particles or atoms with the carrier can induce significant electron transfer, which affects the adsorption of oxygen intermediates and thereby significantly enhances the activity and stability [ 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 ]. Although Ru-based oxide electrocatalysts exhibit high initial OER activity due to their kinetically favorable lattice oxygen oxidation mechanisms, the high-valence oxygen hole intermediate species are highly soluble, resulting in decreased catalytic activity and stability in acidic electrolytes.…”

A new-type high-entropy electrocatalyst with a pyrochlore structure for acid-water oxidation

“…Wu et al 34 demonstrated that the HE rocksalt (MgFeCoNiZn)O presents greater OER performance compared with single rocksalt oxides, which is attributed to the synergy effects between various components and an increase in active sites. Compared to the increase of the intrinsic properties of a material with conventional doping, 35 the structural and property changes resulting from the HE strategy are more signicant. Due to the complexity of HE materials, at present, the potential effects of HE design methods, which induce electronic structures and microstructure characteristics that affect the performance for acid-water oxidation, are elusive and remain unclear.…”