Earth-abundant amorphous catalysts for electrolysis of water

Xu, Wence; Wang, Hongxia

doi:10.1016/s1872-2067(17)62810-9

Cited by 87 publications

(28 citation statements)

References 106 publications

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“…Moreover, some studies have reported that the amorphous phase has advantages in terms of mechanical and electrochemical stability as the disordered structure offers structural stability. [140,141] Various amorphous single metal oxides with high efficiency (e.g., Co, [12,142] Ru, [143] Ni, [144,145] Ir, [146,147] and Mn [148,149] ) have been developed and have outperformed their crystalline counterparts. Considering the good performance of multimetal oxides in crystalline catalysts, the benefits of mixing two or more metals are also expected in amorphous catalysts.…”

Section: Amorphous Metal Oxidesmentioning

confidence: 99%

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

Kim

et al. 2018

Advanced Energy Materials

719

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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Section: Amorphous Metal Oxidesmentioning

confidence: 99%

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

Kim

et al. 2018

Advanced Energy Materials

719

498

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“…It is worth noting that nanomaterials with low crystallinity have been found to outperform their crystalline counterparts in electrocatalytic water splitting [24–27] . Firstly, they always possess small particle size and large surface area, which will expose more active sites for catalytic reaction [28] .…”

Section: Introductionmentioning

confidence: 99%

Constructing RuCoO_x/NC Nanosheets with Low Crystallinity within ZIF‐9 as Bifunctional Catalysts for Highly Efficient Overall Water Splitting

Tuo

Liu

Chen

et al. 2021

Chemistry An Asian Journal

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Electrocatalysts play a pivotal role in accelerating the sluggish electrochemical water splitting reaction. Herein, a Ru−Co oxides and carbon nitrides hybrid (RuCoOx/NC) electrocatalyst was constructed by employing ZIF‐9 to disperse Ru precursor and deliberately regulating the calcination temperature. The moderate calcination temperature results in the RuCoOx nanocomposites with small particle size and low crystallinity as well as the co‐existence of multi‐valence metal compounds, thus boosting the amount and species of active sites. Moreover, the strong interactions between Co and Ru species induce the electron transfer from Co to Ru, thus enhancing the adsorption of anion intermediates on the electron‐deficient Co species and the proton capturing capacity of electron‐sufficient Ru species. As a result, the optimized RuCoOx/NC‐350 catalyst behaved good electrocatalytic activities with 73 and 210 mV overpotential to achieve 10 mA cm−2 for HER and OER, respectively. Remarkably, it showed good durability by holding at 100 mA cm−2 for 100 h in HER and 50 mA cm−2 for 24 h in OER with small activity decline. This study may shed new light on the rational construction of highly efficient Ru‐based catalysts for electrochemical water splitting.

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“…13 It is worth noting that amorphous materials are a kind of promising catalysts for improving water electrolysis efficiency, which is because of the advantages over crystalline materials: larger electrochemical surface area and rich coordinatively unsaturated sites as catalytic centers to improving the catalytic activity. 14,15 Chen et al reported a CoO/MoO x catalyst with a crystalline/amorphous structure; the onset potential for OWS is 1.53 V. 16 Sun et al prepared amorphous NiFe-Borate layer coating NiFe-LDH nanoarray on carbon cloth; the OER overpotential at 50 mA cm −2 is 294 mV. 17 Furthermore, multimetal oxide is also favorable to enhance catalytic activity because the diversity of metal compositions can offer more possible approaches to design catalysts.…”

Section: ■ Introductionmentioning

confidence: 99%

Amorphous CoO_x-Decorated Crystalline RuO₂ Nanosheets as Bifunctional Catalysts for Boosting Overall Water Splitting at Large Current Density

Qian

et al. 2020

ACS Sustainable Chem. Eng.

122

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Developing efficient bifunctional water electrolysis catalysts applied at large current density is desirable. Herein, an amorphous CoO xdecorated crystalline RuO 2 nanosheet catalyst self-supported on nickel foam (CoO x −RuO 2 /NF) with high performance for both oxygen and hydrogen evolution reaction (OER and HER) is prepared successfully by hydrothermal method and annealing. The overpotentials at ±1500 mA cm −2 for OER and HER are 420 and 215 mV, respectively, in 1.0 M KOH solution. Remarkably, it shows good durability with small decline in performance after 48 h durability test for OER and HER at ±1500 mA cm −2 . Furthermore, it only needs 1.49 V to reach 10 mA cm −2 for overall water splitting (OWS); the decline of activity is satisfactory after 48 h durability test at 1500 mA cm −2 . The reason could be because of the sufficient active sites generated by the crystalline−amorphous combination and self-supporting nanosheet structure. This work therefore proposes an effective strategy for preparing a high-performance OWS catalyst, especially at large current density.

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Earth-abundant amorphous catalysts for electrolysis of water

Cited by 87 publications

References 106 publications

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

Constructing RuCoO_x/NC Nanosheets with Low Crystallinity within ZIF‐9 as Bifunctional Catalysts for Highly Efficient Overall Water Splitting

Amorphous CoO_x-Decorated Crystalline RuO₂ Nanosheets as Bifunctional Catalysts for Boosting Overall Water Splitting at Large Current Density

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Earth-abundant amorphous catalysts for electrolysis of water

Cited by 87 publications

References 106 publications

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

Constructing RuCoOx/NC Nanosheets with Low Crystallinity within ZIF‐9 as Bifunctional Catalysts for Highly Efficient Overall Water Splitting

Amorphous CoOx-Decorated Crystalline RuO2 Nanosheets as Bifunctional Catalysts for Boosting Overall Water Splitting at Large Current Density

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Resources

About

Constructing RuCoO_x/NC Nanosheets with Low Crystallinity within ZIF‐9 as Bifunctional Catalysts for Highly Efficient Overall Water Splitting

Amorphous CoO_x-Decorated Crystalline RuO₂ Nanosheets as Bifunctional Catalysts for Boosting Overall Water Splitting at Large Current Density