An efficient defect engineering strategy to enhance catalytic performances of Co3O4 nanorods for CO oxidation

Feng, Bo; Shi, Min; Liu, Junxian; Han, Xinchen; Lan, Zijie; Gu, Hui; Wang, Xiaoxu; Sun, Huamin; Zhang, Qingxiao; Li, Hexing; Wang, Yun; Li, Hui

doi:10.1016/j.jhazmat.2020.122540

Cited by 58 publications

(30 citation statements)

References 58 publications

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“…In this regard, engineering surface defects on widely used metal oxide supports is both academically interesting and industrially useful. For example, defect-engineered TiO 2 has been reported as an efficient photocatalytic material for various reactions, with the fine-tuned TiO 2 exhibiting enhanced visible light response. , The surface defects on TiO 2 could help disperse and stabilize PGMs and tune the electronic states, thus adjusting their catalytic performance. − This approach has also been widely applied to ZnO, Co 3 O 4 , and Nb 2 O 5 for CO/HCs oxidation reactions. − The surface defects on these metal oxides were found to enhance the interaction between PGMs and supports, to facilitate the adsorption, activation, and transfer of active oxygen, and thus to promote the catalytic oxidation performance.…”

Section: Introductionmentioning

confidence: 99%

Transformation of Highly Stable Pt Single Sites on Defect Engineered Ceria into Robust Pt Clusters for Vehicle Emission Control

Tan

Xie

Cai

et al. 2021

Environ. Sci. Technol.

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Engineering surface defects on metal oxide supports could help promote the dispersion of active sites and catalytic performance of supported catalysts. Herein, a strategy of ZrO 2 doping was proposed to create rich surface defects on CeO 2 (CZO) and, with these defects, to improve Pt dispersion and enhance its affinity as single sites to the CZO support (Pt/CZO). The strongly anchored Pt single sites on CZO support were initially not efficient for catalytic oxidation of CO/C 3 H 6 . However, after a simple activation by H 2 reduction, the catalytic oxidation performance over Pt/CZO catalyst was significantly boosted and better than Pt/CeO 2 . Pt/CZO catalyst also exhibited much higher thermal stability. The structural evolution of Pt active sites by H 2 treatment was systematically investigated on aged Pt/CZO and Pt/CeO 2 catalysts. With H 2 reduction, ionic Pt single sites were transformed into active Pt clusters. Much smaller Pt clusters were created on CZO (ca. 1.2 nm) than on CeO 2 (ca. 1.8 nm) due to stronger Pt-CeO 2 interaction on aged Pt/CZO. Consequently, more exposed active Pt sites were obtained on the smaller clusters surrounded by more oxygen defects and Ce 3+ species, which directly translated to the higher catalytic oxidation performance of activated Pt/CZO catalyst in vehicle emission control applications.

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Section: Introductionmentioning

confidence: 99%

Transformation of Highly Stable Pt Single Sites on Defect Engineered Ceria into Robust Pt Clusters for Vehicle Emission Control

Tan

Xie

Cai

et al. 2021

Environ. Sci. Technol.

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“…Among of them, CO is an odorless, colorless, and tasteless toxic gas . Hence, the research of advanced catalysts becomes an active field since the exhaust aftertreatment systems are being developed to meet higher emission standards. , Catalytic oxidation of CO is always one of the most typical catalytic reactions in industrial application. − The greatest future challenge is that the catalysts are active at lower temperatures but also must withstand hydrothermal aging and poisoning (water and sulfur). ,− Single-atom catalysts (SACs) with nearly 100% dispersion of active atoms, first reported by Zhang et al in 2011, exhibit dramatically enhanced mass activity because of the coordination structure different from bulk catalysts . Pt SACs dispersed on typical supports such as Al 2 O 3 have been widely used in catalytic oxidation. − However, the relatively weak interaction between Pt and Al 2 O 3 cannot prevent the Pt agglomeration induced by high surface free energy of metal atoms under harsh conditions such as hydrothermal aging and long-term working .…”

Section: Introductionmentioning

confidence: 99%

A Hydrothermally Stable Single-Atom Catalyst of Pt Supported on High-Entropy Oxide/Al₂O₃: Structural Optimization and Enhanced Catalytic Activity

Zhao

Lin

et al. 2021

ACS Appl. Mater. Interfaces

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A catalyst with high-entropy oxide (HEO)-stabilized single-atom Pt can afford low-temperature activity for catalytic oxidation and remarkable durability even under harsh conditions. However, HEO is easy to harden during sintering, which results in a few defective sites for anchoring single-atom metals. Herein, we present a sol–gel-assisted mechanical milling strategy to achieve a single-atom catalyst of Pt-HEO/Al2O3. The strong interaction between HEO and Al2O3 effectively inhibits the growth of HEO microparticles, which leads to generation of more surface defects because of the nanoscale effect. Meanwhile, another strong interaction between Pt and HEO stabilizes single-atom Pt on HEO. Temperature-programmed techniques further verify that the reactivity of surface lattice oxygen species is enhanced because of the Pt–O–M bonds on the surface of HEO. Unlike conventional single-atom Pt catalysts, Pt-HEO/Al2O3 as a heterogeneous catalyst not only exhibits superior stability against hydrothermal aging but also presents long-term reaction stability for CO catalytic oxidation, which exceeds 540 h. The present work opens a new door for rational design of hydrothermally stable single-atom Pt catalysts, which are highly promising in practical applications.

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“…In addition, a second set of Co 2p peaks at higher binding energies were observed for the CoFe- x samples, ∼1.5–2.0 eV above the main Co 2+ signals. We attribute this additional set of signals to electron-deficient Co atoms (i.e., Co 2 + defect species). ,– Figure f shows the Co 2 + defect/Co 2+ ratios for the various CoFe- x samples, with the ratio increasing on going from CoFe-200 to CoFe-500, then decreasing on going from CoFe-500 to CoFe-800. The analysis suggests that CoFe-500 contains the most cobalt defects, in good accord with the findings the Co K-edge XAS and EXAFs measurements above .…”

Section: Resultsmentioning

confidence: 99%

Exploiting Co Defects in CoFe-Layered Double Hydroxide (CoFe-LDH) Derivatives for Highly Efficient Photothermal Cancer Therapy

Wang

Yang

et al. 2020

ACS Appl. Mater. Interfaces

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Currently, two-dimensional materials are being actively pursued in catalysis and other fields due their abundance of defects, which results in enhanced performance relative to their bulk defect-free counterparts. To date, the exploitation of defects in two-dimensional materials to enhance photothermal therapies has received little attention, motivating a detailed investigation. Herein, we successfully fabricated a series of novel CoFe-based photothermal agents (CoFe-x) by heating CoFe-layered double hydroxide (CoFe-LDH) nanosheets at different temperatures (x) between 200–800 °C under a Ar atmosphere. The CoFe-x products differed in their particle size, cobalt defect concentration, and electronic structure, with the CoFe-500 product containing the highest concentration of Co2+ defects and most efficient photothermal performance under near-infrared (NIR, 808 nm) irradiation. Experiments and density functional theory (DFT) calculations revealed that Co2+ defects modify the electronic structure of CoFe-x, narrowing the band gap and thus increasing the nonradiative recombination rate, thereby improving the NIR-driven photothermal properties. In vitro and in vivo results demonstrated that CoFe-500 was an efficient agent for photothermal cancer treatment and also near-infrared (NIR) thermal imaging, magnetic resonance (MR) imaging, and photoacoustic (PA) imaging. This work provides valuable new insights about the role of defects in the rational design of nanoagents with optimized structures for improved cancer therapy.

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An efficient defect engineering strategy to enhance catalytic performances of Co3O4 nanorods for CO oxidation

Cited by 58 publications

References 58 publications

Transformation of Highly Stable Pt Single Sites on Defect Engineered Ceria into Robust Pt Clusters for Vehicle Emission Control

Transformation of Highly Stable Pt Single Sites on Defect Engineered Ceria into Robust Pt Clusters for Vehicle Emission Control

A Hydrothermally Stable Single-Atom Catalyst of Pt Supported on High-Entropy Oxide/Al₂O₃: Structural Optimization and Enhanced Catalytic Activity

Exploiting Co Defects in CoFe-Layered Double Hydroxide (CoFe-LDH) Derivatives for Highly Efficient Photothermal Cancer Therapy

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An efficient defect engineering strategy to enhance catalytic performances of Co3O4 nanorods for CO oxidation

Cited by 58 publications

References 58 publications

Transformation of Highly Stable Pt Single Sites on Defect Engineered Ceria into Robust Pt Clusters for Vehicle Emission Control

Transformation of Highly Stable Pt Single Sites on Defect Engineered Ceria into Robust Pt Clusters for Vehicle Emission Control

A Hydrothermally Stable Single-Atom Catalyst of Pt Supported on High-Entropy Oxide/Al2O3: Structural Optimization and Enhanced Catalytic Activity

Exploiting Co Defects in CoFe-Layered Double Hydroxide (CoFe-LDH) Derivatives for Highly Efficient Photothermal Cancer Therapy

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A Hydrothermally Stable Single-Atom Catalyst of Pt Supported on High-Entropy Oxide/Al₂O₃: Structural Optimization and Enhanced Catalytic Activity