Engineering High‐Energy Interfacial Structures for High‐Performance Oxygen‐Involving Electrocatalysis

Abstract

Engineering high-energy interfacial structures for high-performance electrocatalysis is achieved by chemical coupling of active CoO nanoclusters and high-index facet Mn 3 O 4 nano-octahedrons (hi-Mn 3 O 4 ). At horough characterization, including synchrotron-based near edge X-raya bsorption fine structure,reveals that strong interactions between both components promote the formation of high-energy interfacial Mn-O-Co species and high oxidation state CoO,f rom which electrons are drawn by Mn III -O present in hi-Mn 3 O 4 .The CoO/ hi-Mn 3 O 4 demonstrates an excellent catalytic performance over the conventional metal oxide-based electrocatalysts,which is reflected by 1.2 times higher oxygen evolution reaction (OER) activity than that of Ru/C and ac omparable oxygen reduction reaction (ORR) activity to that of Pt/C as well as ab etter stability than that of Ru/C (95 %v s. 81 %r etained OER activity) and Pt/C (92 %vs. 78 %retained ORR activity after 10 hrunning) in alkaline electrolyte.A proper interfacial structure of heterogeneous catalysts is of great importance because it can promote the catalytic reactions occurring on the surface.[1] High-energy interfacial structures can facilitate adsorption of reactants on the surface of the catalyst, and charge transport, which result in enhancing catalytic performance.[2] Fori nstance,h eterogeneous catalysts composed of Cu and ZnO nanoparticles on Al 2 O 3 supports are effectively used for industrial production of methanol because ahigh-energy interface between Cu, ZnO, and Al 2 O 3 support can enable astrong binding of the reaction intermediates that improves catalytic activity.[3] Thec oordinatively unsaturated ferrous sites are active centers in awide range of catalytic reactions,and their catalytic activity can be significantly enhanced through high-energy interfacial confinement with metal substrates,e .g., Pt, exhibiting efficient carbon monoxide oxidation.[4] Thereby,the rational design of active materials on proper supports to generate high-energy interfacial structures is critical in fabricating high-performance heterogeneous catalysts.Oxygen-involving electrocatalytic reactions such as oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are important energy-relevant conversion processes, [5] which play important roles in metal-air batteries, fuel cells,and water electrolysis.Both OER and ORR involve am ultistep proton-coupled electron transfer, and thus suffer from ak inetically sluggish process.[6] Moreover,s ome technologies such as rechargeable metal-air batteries reversibly involve OER and ORR during the operation, and the use of two different electrocatalysts for OER (e.g.,R u) and ORR (e.g.,Pt) makes these devices much more complex because of combining two different electrodes;a lso,t heir volumetric energy density is unfavorable.[7] Thus,h igh-performance bifunctional oxygen-involving electrocatalysts are highly desirable.Recently,t here is ag reat interest in fabricating nanostructured composite materials by depositing abundan...

Nanoscale Trimetallic Metal–Organic Frameworks Enable Efficient Oxygen Evolution Electrocatalysis

“…In addition, due to the rarity and high costs even the state‐of‐the‐art catalysts cannot satisfy the scale‐up applications yet . Therefore, tremendous efforts have been devoted to develop highly efficient and stable OER catalysts through tuning the components and composition, such as metal oxides, hydroxides, chalcogenides, nitrides, phosphides and the carbon‐based materials …”

Defect‐Rich Heterogeneous MoS2/NiS2 Nanosheets Electrocatalysts for Efficient Overall Water Splitting

“…[18][19][20] Further, interface modification could be another effective approach to engineering the physical or chemical properties of electrocatalysts. [23,24] Additionally, owing to the different chemical reactivity, there are abundant interior defects in bimetal sulfide hybrids. [23,24] Additionally, owing to the different chemical reactivity, there are abundant interior defects in bimetal sulfide hybrids.…”

Strongly Coupled CoO Nanoclusters/CoFe LDHs Hybrid as a Synergistic Catalyst for Electrochemical Water Oxidation

“…Thereby, for M‐CoO/CoFe LDHs, where the Co/Fe ratio for the LDHs portion of the composite is less than 3.02:1 (Table S1, Supporting Information), the oxidation state of cobalt within the LDHs would not be affected by Fe 3+ concentration. Thus, the presence of Co 3+ in the composite should be ascribed to the strong electronic coupling between CoO NCs and CoFe LHDs at the hybrid interface, which leads to migration of Co electron cloud and induces Co ions with higher oxidation states, highly desirable for OER activity enhancement . The origin of the Co electron transfer was further investigated.…”