Synergy of Ru and Ir in the Electrohydrogenation of Toluene to Methylcyclohexane on a Ketjenblack-Supported Ru-Ir Alloy Cathode

Inami, Yuta; Ogihara, Hitoshi; Nagamatsu, Shin‐ichi; Asakura, Kiyotaka; Yamanaka, Ichiro

doi:10.1021/acscatal.8b03610

Cited by 49 publications

(62 citation statements)

References 38 publications

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“…The superior catalytic activity and stability of the catalyst are attributed to the strong interaction between silver and the nitrogen atoms of CPAN, which makes the silver better fixed on the CPAN carrier. And the same result can be seen in Figure 6e,f, the binding energy of Cu and Ru change little before and after the cycle, and the value of binding energy of Cu and Ru are not in the scope of the reported work for zero valent state (Cu 0 : 933-932.5 eV, [45][46][47] Ru 0 : 462.2-461.2 eV), [48][49][50][51][52] demonstrating that the Cu/CPAN and Ru/CPAN have excellent stability. From the Figures S23-S25 (Supporting Information) we can know that all elements are uniformly distributed and there are no metal nanoparticles on the CPAN, once again indicating that the metal atom stability is well.…”

Section: Catalytic Activitiessupporting

confidence: 62%

Cyclized Polyacrylonitrile as a Promising Support for Single Atom Metal Catalyst with Synergistic Active Site

Liu

Duan

Liang

et al. 2021

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to the metal nanoparticles, single-atom catalysts (SAC) display superior catalytic activity and selectivity in various metalcatalyzed process by virtue of their atomic dispersion, the highest atomic efficiency, and unsaturated coordination. [1,2] In this fast-developing field, several strategies have been provided for preparing metal single-atom materials, including impregnation strategy, coordination site construction strategy, spatial confinement strategy, defect design strategy, transforming metal nanoparticles into SAC, chemical etching, electrochemical method, etc. Accordingly, various supported metal single atom catalysts, including the most published Pt, Al, Fe, Pd, Co, and Ni, Cu, Au Rh, Ag, etc., have been demonstrated to exhibit good catalytic performance. [2][3][4][5][6] Because of their high surface free energy, single atoms are usually loaded on substrates with high surface area and abundant anchoring sites to prevent aggregation during synthetic and catalytic process. Typical supports include zeolite, [7] COFs/MOFs, [8] defect-rich oxides, sulfides, [9,10] nitrides, [11,12] carbon materials [13,14] and polymers. [15] When a single atom is well dispersed on the substrate, the metal-support interaction and coordination environment will change accordingly. In this regard, the support has a significant impact on tailoring the catalytic activity, selectivity and stability of a single atom.The polymers containing N, P, and S species were usually applicative to synthesize SAC via the strong coordination interaction. The reported methods usually require a pyrolysis process to produce heteroatom-doped carbon substrate that provides the coordination environment of anchoring metal atom. Chen et al. reported that single atom Fe catalysts with different coordination sites were fabricated by the pyrolysis of Fe-polyphthalocyanine at temperatures from 500-700 °C. [16] Perez-Ramirez and co-workers designed single gold atoms on nitrogen-doped carbon from polyaniline pyrolysis at 800 °C for molecular recognition in alkyne semi-hydrogenation and the single-atom Au/NC-T catalysts show selective structure sensitivity for different groups. [17] Because polymer materials need to be calcined at high temperatures, the processing properties of carbon materials become extremely poor, and it is difficult to further prepare catalysts for film formation or other shapes, which is conducive to industrial production. Based on this, Metal single atom catalysts (SAC) have been successfully used in heterogeneous catalysis but developing a scalable and economic support for SAC is still a great challenge. Here, cyclized polyacrylonitrile (CPAN) is proposed as a promising support for single atom metal catalysts. CPAN can be easily prepared from cheap industrial product polyacrylonitrile (PAN), which has excellent processability. A series of SAC on CPAN (M/CPAN, M = Ag, Cu, Ru) are designed and the catalytic activities of the as synthesized M/CPAN are investigated by the model reduction reaction of p-nitrophenol (4-NP). M/CPAN presents ex...

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Section: Catalytic Activitiessupporting

confidence: 62%

Cyclized Polyacrylonitrile as a Promising Support for Single Atom Metal Catalyst with Synergistic Active Site

Liu

Duan

Liang

et al. 2021

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“…The excellent performance of SVF cathode was due to the sufficient porous architecture, which precisely improved the wettability, accessibility, and absorption of electrolyte to facilitate fast ion transfer in the Li‐S cell. Ketjenblack (KB) is a carbon material with unique morphology and very big specific surface area (1400 m 2 g −1 ) . Its conductivity is three times higher than that of traditional conductive agents such as acetylene black (AB) .…”

Section: Cathodementioning

confidence: 99%

A Review: Electrospun Nanofiber Materials for Lithium‐Sulfur Batteries

Liu

Deng

et al. 2019

Adv Funct Materials

152

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Lithium-sulfur (Li-S) batteries are in the spotlight because their outstanding theoretical specific energy is much higher than those of the commercial lithium ion (Li-ion) batteries. Li-S batteries are tough competitors for futuredeveloping energy storage in the fields of portable electronics and electric vehicles. However, the severe "shuttle effect" of the polysulfides and the serious damage of lithium dendrites are main factors blocking commercial production of Li-S batteries. Owing to their superior nanostructure, electrospun nanofiber materials commonly show some unique characteristics that can simultaneously resolve these issues. So far, various novel cathodes, separators, and interlayers of electrospun nanofiber materials which are applied to resolve these challenges are researched. This review presents the fundamental research and technological development of multifarious electrospun nanofiber materials for Li-S cells, including their processing methods, structures, morphology engineering, and electrochemical performance. Not only does the review article contain a summary of electrospun nanofiber materials in Li-S batteries but also a proposal for designing electrospun nanofiber materials for Li-S cells. These systematic discussions and proposed directions can enlighten thoughts and offer ways in the reasonable design of electrospun nanofiber materials for excellent Li-S batteries in the near future.or conducting coagulation bath) is placed against the capillary. A thin polymer fiber membrane is deposited on the collector. The electrospun nanofibers have big potential for developing the outstanding energy storage systems due to their high surface area and excellent surface-to-volume ratio which can offer numerous active sites and controllable porous structure to buffer the huge volume changes during battery cycling and infiltrate the electrolyte. [18] Electrospun nanofiber membranes possess high porosity, large specific surface area, and controllable pore size, which will block "shuttle effect" of polysulfides and enhance the wettability for electrolytes. [19] Electrospinning technique and carbonization process are facile to manufacture freestanding nanofiber fabrics with controllable porous architecture and outstanding electrical conductivity. Electrospun porous nanofibers can come into a reservoir-like matrix for the reserve of active materials. First, the hierarchical pores in electrospun porous nanofibers can improve the reactive S reaction sites and block soluble polysulfides, thereby decreasing the "shuttling effect" of polysulfides during the electrochemical cycling. Second, electrospun porous fibers have excellent physical and mechanical properties, outstanding architecture, and superior electrical conductivity, which can enhance the transfer of Li-ions and electrons, endowing extraordinary electrochemical performance of the whole battery system. [20] Figure 2 shows phase and morphological evolutions of the electrospun nanofibers. By combining the electrospinning and other treatment (thermal, chem...

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“…14,15 Electrochemistry can be an elegant substitute for such sacrificial electron donors, which has led to a third branch of hydrogenation catalysis, namely electrocatalytic hydrogenation (ECH). Remarkable examples of ECH have been reported for the conversion of alkenes to alkanes, 16,17 selective semi-hydrogenation of alkynes to alkenes, 18,19 exhaustive hydrogenation of arenes, [20][21][22] selective hydrogenation of arenes to 1,4dienes, 23 hydrogenation of organic carbonyls, 24,25 or the de-oxygenation of biomass. [26][27][28] ECH has even proven to be a powerful method for the synthesis of selectively deuterated alkenes.…”

Section: Introductionmentioning

confidence: 99%

Proton Independent Electrocatalytic Transfer Hydrogenation of Styrene with [(tBuPCP)Ir(H)(Cl)] and Water

Mollik

Frantz

Halter

2022

Preprint

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A new pathway of electrocatalytic transfer hydrogenation with neutral water as the H-donor was discovered using [(tBuPCP)Ir(H)(Cl)] (1) as the catalyst and styrene as a model substrate in THF electrolyte. Cyclic voltammetry experiments with 1 revealed that two subsequent reductions at –2.55 and –2.84 V vs. Fc+/Fc trigger the elimination of Cl– and afford the highly reactive anionic Ir(I) hydride complex [(tBuPCP)Ir(H)]– (2). The identity of 2 and its reactivity were further investigated by LIFDI-MS, which confirmed 2 as reactive species in the alkene hydrogenation cycle. Bulk electrolysis and chronoamperometry for electro-hydrogenation of styrene established ethylbenzene as the only product, formed with high faradaic efficiency of 96% and a turnover frequency of 1670 h–1 at an electrolysis potential of –3.1 V, with insignificant H2 formation. Importantly, the electro-hydrogenation performance of 1 remained constant upon addition of KOH to the electrolyte, which suggests a reaction mechanism that is independent of free H+. Instead, the reactive Ir-hydrides are regenerated by oxidative addition of H2O to the complex, which creates a reaction cascade that is reminiscent of metal-hydride formation in classical transfer hydrogenation systems. As such, the herein presented study on electrocatalytic transfer hydrogenation (e-TH) with H2O as the H-donor is different from the plethora of other electro-hydrogenation studies that operate via H+ reduction, often in low-pH electrolyte. These findings may inspire the general, pH independent use of H2O as H-donor in conjunction with electrochemistry, to replace isopropanol or formate as intrinsically reducing H-donors in the many existing examples of classical transfer hydrogenation.

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Synergy of Ru and Ir in the Electrohydrogenation of Toluene to Methylcyclohexane on a Ketjenblack-Supported Ru-Ir Alloy Cathode

Cited by 49 publications

References 38 publications

Cyclized Polyacrylonitrile as a Promising Support for Single Atom Metal Catalyst with Synergistic Active Site

Cyclized Polyacrylonitrile as a Promising Support for Single Atom Metal Catalyst with Synergistic Active Site

A Review: Electrospun Nanofiber Materials for Lithium‐Sulfur Batteries

Proton Independent Electrocatalytic Transfer Hydrogenation of Styrene with [(tBuPCP)Ir(H)(Cl)] and Water

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