Unveiling reductant chemistry in fabricating noble metal aerogels for superior oxygen evolution and ethanol oxidation

Du, Ran; Wang, Jinying; Wang, Ying; Hübner, René; Fan, Xuelin; Senkovska, Irena; Hu, Yue; Kaskel, Stefan; Eychmüller, Alexander

doi:10.1038/s41467-020-15391-w

Cited by 132 publications

(173 citation statements)

References 47 publications

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“…As illustrated in Figure a, the peaks during the forward scan and the backward scan denote the oxidation of the ethanol and the oxidation of the intermediates generated during the forward scan, respectively . The Au‐Pt aerogel and the Au‐Pd aerogel exhibit forward current densities ( I f ) of 3.5 and 8.4 A mg −1 , respectively, much larger than those of commercial Pt/C (0.9 A mg −1 ) and Pd/C (1.8 A mg −1 ).…”

Section: Resultsmentioning

confidence: 99%

Freeze–Thaw‐Promoted Fabrication of Clean and Hierarchically Structured Noble‐Metal Aerogels for Electrocatalysis and Photoelectrocatalysis

Joswig

Hübner

et al. 2020

Angew Chem Int Ed

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Noble‐metal aerogels (NMAs) have drawn increasing attention because of their self‐supported conductive networks, high surface areas, and numerous optically/catalytically active sites, enabling their impressive performance in diverse fields. However, the fabrication methods suffer from tedious procedures, long preparation times, unavoidable impurities, and uncontrolled multiscale structures, discouraging their developments. By utilizing the self‐healing properties of noble‐metal aggregates, the freezing‐promoted salting‐out behavior, and the ice‐templating effect, a freeze–thaw method is crafted that is capable of preparing various hierarchically structured noble‐metal gels within one day without extra additives. In light of their cleanliness, the multi‐scale structures, and combined catalytic/optical properties, the electrocatalytic and photoelectrocatalytic performance of NMAs are demonstrated, which surpasses that of commercial noble‐metal catalysts.

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Section: Resultsmentioning

confidence: 99%

Freeze–Thaw‐Promoted Fabrication of Clean and Hierarchically Structured Noble‐Metal Aerogels for Electrocatalysis and Photoelectrocatalysis

Joswig

Hübner

et al. 2020

Angew Chem Int Ed

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“…As shown in Table S1 in the Supporting Information, PtBi@PtRh 1 nanoplates exhibit a high electrocatalytic performance toward EOR in alkaline electrolyte, outperforming current state-of-theart high-performance electrocatalysts. [2,15,42,[56][57][58][59] It should be noted that, although such unique tensile-strained SAA nanoplates are not directly achieved by a wet-chemical co-deposition method, it is already possible to scale up the synthesis of this nanostructured catalyst to ≈200 mg per batch (Figure S40, the Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

A Tensile‐Strained Pt–Rh Single‐Atom Alloy Remarkably Boosts Ethanol Oxidation

et al. 2021

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which is also considered a biorenew able energy carrier. However, the anodic ethanol oxidation reaction (EOR) is a complicated and kinetically sluggish process, involving the transfer of multiple electrons and various reaction intermediates and products. Typically, the C2-pathway dominates the EOR in both acidic and alkaline electrolytes, resulting in the formation of acetic acid or acetate by delivering four electrons, and acetaldehyde by delivering two electrons, respectively. The C1-pathway, which involves complete oxidation and the transfer of 12 electrons generating CO 2 or carbonate, is preferred to the C2-pathway, aiming for maximum DEFCs efficiency. [1][2][3][4][5] Specially, highly efficient catalysts have been developed by engineering Pt-based nanocrystals, and the C1-pathway selectivity has been promoted by Rh-based catalysts. [6][7][8][9] In designing electrochemical surfaces toward maximum performance, modifying the electronic structure and strain of catalytic surfaces are considered state-of-the-art strategies, which can for instance be achieved by introducing metals with different intrinsic reactivities and constructing core-shell nanostructures, respectively. [10][11][12][13][14][15] Combining these approaches in a rational manner would be a promising way to substantially improve the EOR, yet the underlying knowledge about their contributions is largely lacking. [10][11][12][13][14][15][16][17][18] Therefore, it is highly desirable to employ tailored nanostructures to resolve these important issues and contribute to the practical deployment of DEFCs by identifying versatile EOR electrocatalysts possessing high atom utilization of noble metals, high mass-normalized activity at low overpotentials, high C1-pathway selectivity, long-term durability, and superior anti-poisoning ability. [1] To maximize atom utilization, single-atom catalysts (SACs) have emerged as one of the most promising frontiers in materials chemistry. [19][20][21] Using specific support materials such as reducible metal oxides, activated carbons, and anisotropic materials such as MoS 2 , single atoms of catalytically metals can be stabilized, which exhibit intriguing physicochemical properties compared with their counterpart clusters and nanoparticles. [22][23][24] Typically, high-performance EOR catalysts should facilitate multiple dehydrogenation and oxidation steps as well as CC bond cleavage reactions. All these reactions typically require ensembles of surface metal atoms, implying that thisThe rational design and control of electrocatalysts at single-atomic sites could enable unprecedented atomic utilization and catalytic properties, yet it remains challenging in multimetallic alloys. Herein, the first example of isolated Rh atoms on ordered PtBi nanoplates (PtBi-Rh 1 ) by atomic galvanic replacement, and their subsequent transformation into a tensile-strained Pt-Rh single-atom alloy (PtBi@PtRh 1 ) via electrochemical dealloying are presented. Benefiting from the Rh 1 -tailored Pt (110) surface with tensile strain, the PtBi@...

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“…[31] Several studies describe factors which influence the electrostatic forces and therefore the self-assembly like pH value,s urface charge,o r solvent but ageneralizing theory for precisely controlling selfassembly and gelation is still missing. [32][33][34][35] Also,the pH value and the charge of the NPs influence the attachment at the phase boundary between the liquids which should also influence the gelation. [36,37] Thec hange of the NaBH 4 concentration affects many of these described factors.…”

Section: Resultsmentioning

confidence: 99%

Tailoring the Morphology and Fractal Dimension of 2D Mesh‐like Gold Gels

et al. 2020

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As there is a great demand of 2D metal networks, especially out of gold for a plethora of applications we show a universal synthetic method via phase boundary gelation which allows the fabrication of networks displaying areas of up to 2 cm 2 . They are transferred to many different substrates: glass, glassy carbon, silicon, or polymers such as PDMS. In addition to the standardly used web thickness, the networks are parametrized by their fractal dimension. By variation of experimental conditions, we produced web thicknesses between 4.1 nm and 14.7 nm and fractal dimensions in the span of 1.56 to 1.76 which allows to tailor the structures to fit for various applications. Furthermore, the morphology can be tailored by stacking sheets of the networks. For each different metal network, we determined its optical transmission and sheet resistance. The obtained values of up to 97 % transparency and sheet resistances as low as 55.9 Ω/sq highlight the great potential of the obtained materials.

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Unveiling reductant chemistry in fabricating noble metal aerogels for superior oxygen evolution and ethanol oxidation

Cited by 132 publications

References 47 publications

Freeze–Thaw‐Promoted Fabrication of Clean and Hierarchically Structured Noble‐Metal Aerogels for Electrocatalysis and Photoelectrocatalysis

Freeze–Thaw‐Promoted Fabrication of Clean and Hierarchically Structured Noble‐Metal Aerogels for Electrocatalysis and Photoelectrocatalysis

A Tensile‐Strained Pt–Rh Single‐Atom Alloy Remarkably Boosts Ethanol Oxidation

Tailoring the Morphology and Fractal Dimension of 2D Mesh‐like Gold Gels

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