Unification of Catalytic Water Oxidation and Oxygen Reduction Reactions: Amorphous Beat Crystalline Cobalt Iron Oxides

Indra, Arindam; Menezes, Prashanth W.; Sahraie, Nastaran Ranjbar; Bergmann, Arno; Das, Chittaranjan; Tallarida, Massimo; Schmeißer, Dieter; Strasser, Peter; Drieß, Matthias

doi:10.1021/ja509348t

Cited by 597 publications

(455 citation statements)

References 121 publications

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“…On the CoP and a‐CoOx nanointerfaces, the OH − could preferentially attach to a a‐CoOx site at the interface due to strong electrostatic affinity to the locally positively charged Co 2+ /Co 3+ species and more empty d orbitals in Co 2p than that in CoP, while a nearby CoP site would facilitate H adsorption; suggesting synergistic electrocatalytic activity to CoP@a‐CoOx plate. Furthermore, to clarify the roles of each component, i.e., amorphous cobalt oxides or cobalt phosphides, the CoP particles (CoP‐p) were prepared according to the phosphating process of cobalt chloride while amorphous cobalt oxides (a‐CoOx‐p) were prepared following the procedure of the previous report 11. The powder XRD patterns of CoP‐p and a‐CoOx‐p confirmed the presence of crystalline CoP phase (JCPDS No.…”

Section: Resultsmentioning

confidence: 94%

Bifunctionality from Synergy: CoP Nanoparticles Embedded in Amorphous CoOx Nanoplates with Heterostructures for Highly Efficient Water Electrolysis

Zhong

et al. 2018

Advanced Science

142

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Hydrogen production from renewable electricity relies upon the development of an efficient alkaline water electrolysis device and, ultimately, upon the availability of low cost and stable electrocatalysts that can promote oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Normally, different electrocatalysts are applied for HER and OER because of their different reaction intermediates and mechanisms. Here, the synthesis of a heterostructured CoP@a‐CoOx plate, which constitutes the embedded crystalline cobalt phosphide (CoP) nanoclusters and amorphous cobalt oxides (CoOx) nanoplates matrix, via a combined solvothermal and low temperature phosphidation route is reported. Due to the presence of synergistic effect between CoP nanoclusters and amorphous CoOx nanoplates in the catalyst, created from the strong nanointerfaces electronic interactions between CoP and CoOx phases in its heterostructure, this composite displays very high OER activity in addition to favorable HER activity that is comparable to the performance of the IrO2 OER benchmark and approached that of the Pt/C HER benchmark. More importantly, an efficient and stable alkaline water electrolysis operation is achieved using CoP@a‐CoOx plate as both cathode and anode as evidenced by the obtainment of a relatively low potential of 1.660 V at a 10 mA cm−2 current density and its marginal increase above 1.660 V over 30 h continuous operation.

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Section: Resultsmentioning

confidence: 94%

Bifunctionality from Synergy: CoP Nanoparticles Embedded in Amorphous CoOx Nanoplates with Heterostructures for Highly Efficient Water Electrolysis

Zhong

et al. 2018

Advanced Science

142

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“…Therefore, special attention has been paid to the development of synthetic methods that enable the composition control with a homogeneous distribution of elements. Such synthesis methods include electrodeposition, [29,93,[150][151][152][153][154][155] photochemical metal-organic deposition (PMOD), [156][157][158][159][160] aerosol-sprayassisted processes, [161,162] reactive magnetron co-sputtering, [163] solvothermal processes, [164] and thermal decomposition. [165] …”

Section: Amorphous Metal Oxidesmentioning

confidence: 99%

“…In addition, Indra et al reported on amorphous Co-Fe oxide catalysts prepared using solvothermal synthesis. [164] The crystallinity of the products was controlled by modifying the solvent type and reaction time of the synthesis process, enabling the formation of both amorphous Co-Fe oxide (CoFe 2 O n , n ≈ 3.66) and crystalline Co-Fe oxide (CoFe 2 O 4 ). With respect to both the mass activity and surface normalized activity, the amorphous Co-Fe oxide (η = 370 mV at 400 mA mg −1 , η = 490 mV at 10 mA cm BET −2 ) exhibited much better performance than its crystalline counterpart (η = 510 mV at 370 mA mg −1 , η = 560 mV at 10 mA cm BET…”

Section: Wwwadvenergymatdementioning

confidence: 99%

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

Kim

et al. 2018

Advanced Energy Materials

697

498

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fossil fuels are being widely researched for the development of a sustainable energy system. Among the various candidates for green energy resources, hydrogen energy has been at the center of attention. [1,2] Hydrogen is both inexhaustible and environmentally friendly, because it can be produced from earth-abundant reactants such as water and methane and because no CO 2 or other toxic products are emitted during its conversion into other energy form such as electricity, respectively. Moreover, hydrogen can exhibit significantly larger energy density compared with other energy sources such as gasoline and coal. The most widely used method of hydrogen production today is steam reforming because of its low cost in the process. [3] Nevertheless, the release of carbon monoxide or carbon dioxide as byproducts in the steam reforming process diminishes the environmental merits of hydrogen energy. Thus, as a possible cleaner alternative, an electrolysis method that involves producing hydrogen by electrochemically splitting water has been extensively investigated. Using one of the most abundant resources, water, the production of hydrogen from it yields only oxygen as a byproduct.In the water electrolysis, the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) occur simultaneously, as described by the following equationsIn order for the reaction to proceed, a voltage of 1.23 V is theoretically required between an anode and a cathode. However, an overpotential (represented by the symbol η) should be additionally applied to account for the potential loss resulting from kinetic limitations occurring during the electrochemical reaction. The use of electrocatalysts can lower the overpotential by kinetically facilitating the water-splitting reaction either in HER or OER. Due to the nature of four-electron involving OER, it is generally believed that the OER is much more sluggish than the HER; thus, the development of efficient OER Hydrogen is a promising alternative fuel for efficient energy production and storage, with water splitting considered one of the most clean, environmentally friendly, and sustainable approaches to generate hydrogen. However, to meet industrial demands with electrolysis-generated hydrogen, the development of a low-cost and efficient catalyst for the oxygen evolution reaction (OER) is critical, while conventional catalysts are mostly based on precious metals. Many studies have thus focused on exploring new efficient nonprecious-metal catalytic systems and improving the understandings on the OER mechanism, resulting in the design of catalysts with superior activity compared with that of conventional catalysts. In particular, the use of multimetal rather than single-metal catalysts is demonstrated to yield remarkable performance improvement, as the metal composition in these catalysts can be tailored to modify the intrinsic properties affecting the OER. Herein, recent progress and accomplishments of multimetal catalytic systems, including several important groups of catalysts: layered h...

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“…[32] Spinel oxides (A x B 3−x O 4 ) can be used as bifunctional ORR/OER catalyst in alkaline media. [46] Among spinel oxides, the electron transfer occur with quite low activation energy between the cations of different valences. For example, Chen et al developed a facile and rapid room-temperature method to prepare highly active Co x Mn 3−x O 4 for bifunctional ORR/OER.…”

Section: Mixed-metal Engineeringmentioning

confidence: 99%

Design of Efficient Bifunctional Oxygen Reduction/Evolution Electrocatalyst: Recent Advances and Perspectives

Huang

Wang

Peng

et al. 2017

Advanced Energy Materials

676

448

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Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the two most important reactions in rechargeable metal‐air battery, a promising technology to meet the energy requirements for various applications. The development of low‐cost, highly efficient and stable bifunctional ORR/OER catalysts is critical for a large‐scale application of this technology. In this review, the authors first introduce the fundamentals of bifunctional ORR/OER electrocatalysis in alkaline electrolyte. Various types of nanostructured materials as bifunctional ORR/OER catalysts including metal oxide, hydroxide and sulfide, functional carbon material, metal, and their composites are then reviewed. The crucial factors that can be used to tune the activity of the catalyst towards ORR/OER are summarized, including (1) phase, morphology, crystal facet, defect, mixed‐metal and strain engineering for metal oxide; (2) heteroatom doping, topological defects, and formation of metal‐N‐C structure for carbon material; (3) alloy effect for metal. These experiences lay the foundation for large scale application of metal‐air battery and can also effectively guide the rational design of catalysts for other electrocatalytic reactions.

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Unification of Catalytic Water Oxidation and Oxygen Reduction Reactions: Amorphous Beat Crystalline Cobalt Iron Oxides

Cited by 597 publications

References 121 publications

Bifunctionality from Synergy: CoP Nanoparticles Embedded in Amorphous CoOx Nanoplates with Heterostructures for Highly Efficient Water Electrolysis

Bifunctionality from Synergy: CoP Nanoparticles Embedded in Amorphous CoOx Nanoplates with Heterostructures for Highly Efficient Water Electrolysis

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

Design of Efficient Bifunctional Oxygen Reduction/Evolution Electrocatalyst: Recent Advances and Perspectives

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