Confinement of Ultrasmall Bimetallic Nanoparticles in Conductive Metal–Organic Frameworks via Site‐Specific Nucleation

Park, Chungseong; Koo, Won‐Tae; Chong, Sanggyu; Shin, Hamin; Kim, Yoon Hwa; Cho, Hee Jin; Jang, Ji‐Soo; Kim, Dong-Ha; Lee, Ji-Young; Park, Sung Yong; Ko, Jung Hwa; Kim, Jihan; Kim, Il‐Doo

doi:10.1002/adma.202101216

Cited by 27 publications

(33 citation statements)

References 67 publications

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“…The simplicity of the MOF-assisted ex-solution process also enables the fabrication of bimetallic and multi-metallic systems, of which the multi-elemental synergies are advantageous for heightened catalytic activity. [30] We hereafter focus on PdPt-and PdRh-based catalysts for further studies on material characterization and catalytic activities. The detailed synthesis mechanism for bimetallic systems is described in the discussion accompanying Figure S1, Supporting Information.…”

Section: Resultsmentioning

confidence: 99%

Promoting Ex‐Solution from Metal–Organic‐Framework‐Mediated Oxide Scaffolds for Highly Active and Robust Catalysts

Park

Ahn

et al. 2022

Advanced Materials

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Notably, the ex-solution approach requires only a single-step heat treatment in a reducing environment to transform a doped metal oxide into a supported metal catalyst. Specifically, the reduction of host oxides doped with a metallic element causes the spontaneous precipitation of metal nanoparticles over the oxide surface, during which the oxide forms a socket around the nanoparticles and induces a strong metal-support interaction through the build-up of strain at the metal-oxide interface. Owing to these structural advantages, supported metal catalysts prepared by the ex-solution process exhibit significantly enhanced surface activity as well as thermal and chemical stability, showing much promise for applications as highperformance catalysts in solid oxide cell/ electrolysis, [3][4][5] three-way catalyst, [6][7][8] and chemical looping fields. [9][10][11][12] However, ex-solution-based heterogeneous catalysts suffer from critical issues such as the low surface area of host metal oxides, the limited dopant solubility in metal oxides, and the incomplete conversion of doped cations into metal nanoparticles. The critical issue in preparing ex-solved catalysts arises from the high-temperature processing required to incorporate dopants and precipitate the catalytic nanoparticles over a reservoir oxide, thereby causing grain growth and sintering in the host materials and reducing the active surface area of the oxides. Recently, Gorte and co-workers addressed this obstacle by fabricating thin perovskite films via atomic layer deposition, [13] which has a short diffusion length and therefore enables the dopants to readily ex-solve without structural degradation in the support. Another major challenge is that metals with high stability against ionization during calcination are not readily doped into an oxide matrix. Instead, these metals segregate as particles or form a second phase during synthesis, showing limited solubility in parent materials. As a strategy to retain these metal species in an oxidized state, Irvine's group reported on Ba-stabilized Pt oxides as a Pt precursor that can be easily incorporated into the perovskite lattice, which facilitates the ex-solution of Pt with a controllable content. [14] Overall, these works have greatly contributed to improving the viability of the ex-solution approach.Ex-solution catalysts, in which a host oxide is decorated with confined metallic nanoparticles, have exhibited breakthrough activity in various catalytic reactions. However, catalysts prepared by conventional ex-solution processes are limited by the low surface area of host oxides, the limited solubility of dopants, and the incomplete conversion of doped cations into metal catalysts. Here, the design of the host oxide structure is reconceptualized using a metal-organic framework (MOF) as an oxide precursor that can absorb a large quantity of ions while also promoting ex-solution at low temperatures (400-500 °C). The MOF-derived metal oxide host can readily incorporate metal cations, from which catalytic nanoparti...

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Section: Resultsmentioning

confidence: 99%

Promoting Ex‐Solution from Metal–Organic‐Framework‐Mediated Oxide Scaffolds for Highly Active and Robust Catalysts

Park

Ahn

et al. 2022

Advanced Materials

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“…In summary, an accurate composition control (molar ratio of Pt and Ru = 1 : 1), rather high uniformity and a narrow size distribution (1.54 ± 0.42 nm) of different loadings without a severe loss in the cMOF's conductivity were enabled. 82 This research represents a good example for the exploitation of inherent MOF features perfectly attuned to suitable precursor species for the controlled synthesis of special MA@MOF species. Other noteworthy examples on this topic are the nucleation of noble metal nanodots on redox-active MOFs 89 or the encapsulation of PdAu alloy NPs in MIL-100(Fe).…”

Section: Synthetic Approaches For Ma@mofsmentioning

confidence: 97%

“…In 2021, Park et al 82 succeeded in synthesising well-distributed, confined bimetallic PtRu NPs within the 2D conductive MOF Cu 3 (HHTP) 2 (HHTP: hexahydroxytriphenylene) by site-specific nucleation (Fig. 1).…”

Section: Synthetic Approaches For Ma@mofsmentioning

confidence: 99%

Defined metal atom aggregates precisely incorporated into metal–organic frameworks

et al. 2022

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“…In addition, the photodynamic effect of [Mo 6 I 8 (L′) 6 ] 2− clusters was much higher at L′ = CH 3 COO- than at L′ = I-. In recent years, bimetallic NPs are also improving the therapeutic efficiency of PSs due to the inherent properties of the introduced metal elements and the interaction between two metal atoms ( Park et al, 2021 ). He et al synthesized Au 1 Bi 1 -SR NPs by introducing Bi into captopril-coated Au NPs (Au-SR NPs) by utilizing the X-ray CT signal enhancement effect of Bi He G. et al (2021) .…”

Section: Strategies For Nanoparticle-based Photocontrolled Deliverymentioning

confidence: 99%

Progress of Nanomaterials in Photodynamic Therapy Against Tumor

Chen

Huang

et al. 2022

Front. Bioeng. Biotechnol.

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Photodynamic therapy (PDT) is an advanced therapeutic strategy with light-triggered, minimally invasive, high spatiotemporal selective and low systemic toxicity properties, which has been widely used in the clinical treatment of many solid tumors in recent years. Any strategies that improve the three elements of PDT (light, oxygen, and photosensitizers) can improve the efficacy of PDT. However, traditional PDT is confronted some challenges of poor solubility of photosensitizers and tumor suppressive microenvironment. To overcome the related obstacles of PDT, various strategies have been investigated in terms of improving photosensitizers (PSs) delivery, penetration of excitation light sources, and hypoxic tumor microenvironment. In addition, compared with a single treatment mode, the synergistic treatment of multiple treatment modalities such as photothermal therapy, chemotherapy, and radiation therapy can improve the efficacy of PDT. This review summarizes recent advances in nanomaterials, including metal nanoparticles, liposomes, hydrogels and polymers, to enhance the efficiency of PDT against malignant tumor.

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Confinement of Ultrasmall Bimetallic Nanoparticles in Conductive Metal–Organic Frameworks via Site‐Specific Nucleation

Cited by 27 publications

References 67 publications

Promoting Ex‐Solution from Metal–Organic‐Framework‐Mediated Oxide Scaffolds for Highly Active and Robust Catalysts

Promoting Ex‐Solution from Metal–Organic‐Framework‐Mediated Oxide Scaffolds for Highly Active and Robust Catalysts

Defined metal atom aggregates precisely incorporated into metal–organic frameworks

Progress of Nanomaterials in Photodynamic Therapy Against Tumor

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