Distribution and Valence State of Ru Species on CeO<sub>2</sub> Supports: Support Shape Effect and Its Influence on CO Oxidation

Li, Junhao; Liu, Zhongqi; Cullen, David A.; Hu, Wenhui; Huang, Jier; Yao, Libo; Peng, Zhenmeng; Liao, Peilin; Wang, Ruigang

doi:10.1021/acscatal.9b03113

Cited by 186 publications

(143 citation statements)

References 90 publications

(161 reference statements)

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“…The intrinsic gaseous CO 2 exhibited two peaks at 2335 and 2360 cm −1 , respectively, and gaseous CO preserved its characteristic peak around 2177 cm −1 . [ 18 ] We found that when CO was introduced into the reaction cell, a new peak located at 2110 cm −1 instantly appeared even at the start temperature of 50 °C, clear evidence of linearly adsorbed CO on Pt. [ 5,42 ] This suggested that L‐Pt@CeO 2 catalyst manifested the high affinity toward CO.…”

Section: Figurementioning

confidence: 99%

“…[ 13–17 ] Surface defect engineering of the metal oxide supporting particles has been developed and refined to enhance support coupling with noble MNPs. [ 18–20 ] However, sophisticated pretreatment of the metal oxide supports and complicated synthetic procedures of noble MNPs still hinder their wide applications. It is challenging to establish a straightforward method to synthesize uniform catalysts in which preformed PGM nanoparticles are homogeneously mixed with metal oxide supports via strong surface coupling to retard the aggregation issue.…”

Section: Figurementioning

confidence: 99%

“…Former studies revealed that the oxygen vacancies (O v ) in the CeO 2 support play a critical role for CO oxidation because of their roles in the oxygen storage, redox of CeO 2 , and the interaction with the supported noble metals. [ 18 ] The O v concentrations in L‐Pt@CeO 2 catalysts was investigated by UV Raman spectroscopy. [ 34 ] As shown in Figure 2C, an obvious vibrational peak located around 420–500 cm −1 assigning to F 2g and a weak vibrational peak appeared around 550–600 cm −1 ascribed to D modes of O v were observed in the L‐Pt@CeO 2 catalysts.…”

Section: Figurementioning

confidence: 99%

“…Due to the loss in oxygen, strong coupling would be formed at the Pt and CeO 2 interface to balance the electrons (Figure 1A). [ 18,36 ] Based on this, we can assume that Pt was deposited at the surface of CeO 2 through Pt‐O coordination. Previous studies revealed that surficial O v on CeO 2 support could significantly facilitate the CO oxidation by providing sufficient oxygen for CO absorbed on the surface of noble metals and modifying the electronic structure of the catalysts.…”

Section: Figurementioning

confidence: 99%

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Ultrafast Laser Manufacture of Stable, Efficient Ultrafine Noble Metal Catalysts Mediated with MOF Derived High Density Defective Metal Oxides

Guo

Zhao

Yuan

et al. 2020

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subdivision reduces cost, but nano-and atomic-scale PGM catalysts can suffer from severe aggregation and degradation under practical use conditions. [1][2][3][4][5] This is due to coalescence and Ostwald ripening of metal nanoparticles (MNPs) driven by high surface energy. Catalysts constructed by dispersion of nanosized precious metals on metal oxide supporting particles are widely explored to deal the aggregation issue. [6][7][8][9][10][11][12] However, because of the limited contact between them and the lack of surface bonding to stabilize the MNPs, the deterioration of catalytic efficiency still occurs due to noble metal coalescence, especially under high operating temperature (>500 °C). [13][14][15][16][17] Surface defect engineering of the metal oxide supporting particles has been developed and refined to enhance support coupling with noble MNPs. [18][19][20] However, sophisticated pretreatment of the metal oxide supports and complicated synthetic procedures of noble MNPs still hinder their wide applications. It is challenging to establish a straightforward method to synthesize uniform catalysts in which preformed PGM nanoparticles are homogeneously mixed with metal oxide supports via strong surface coupling to retard the aggregation issue. In addition, metal oxides and PGM nanoparticles with smaller particle size are highly desired because they expose much more surface area and create the enriched active sites for the reaction. [21][22][23] Unfortunately, the established methods, either rely on high temperature calcination or low temperature wet-impregnation, suffer from aggregation of MNPs or weak bonding of the MNPs on the metal oxide supports.Herein, by virtue of metal-organic framework (MOF) incorporation of noble metal ions and advanced ultrafast laser processing, we report the synthesis of uniformly mixed noble metal nanoclusters with sub-2 nm size conjoined on surfacedefective CeO 2 nanoparticles with sub-5 nm size (M@CeO 2 , M = Pt, Au, Rh, Ru). This is achieved by direct laser conversion of cerous MOF (Ce-MOF) incorporated with corresponding noble metal ions under ambient conditions. MOFs, with precisely and atomically arranged metal oxide units jointed by organic linkers, exposed extremely high surface area where Supported metal nanoparticles (MNPs) undergo severe aggregation, especially when the interaction between MNPs and their supports are limited and weak where their performance deteriorates dramatically. This becomes more severe when catalysts are operated under high temperature. Here, it is reported that MNPs including Pt, Au, Rh, and Ru, with sub-2 nm size can be stabilized on densely packed defective CeO 2 nanoparticles with sub-5 nm size via strong coupling by direct laser conversion of corresponding metal ions encapsulated cerous metal-organic frameworks (Ce-MOFs). Ce-MOF serves as an ideal dispersion precursor to uniformly encapsulate noble metal ions in their orderly arranged pores. Ultrafast laser vaporization and cooling forms uniform, ultrasmall, well-mixed, and exceptionally dens...

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Section: Figurementioning

confidence: 99%

Section: Figurementioning

confidence: 99%

Section: Figurementioning

confidence: 99%

Section: Figurementioning

confidence: 99%

See 2 more Smart Citations

Ultrafast Laser Manufacture of Stable, Efficient Ultrafine Noble Metal Catalysts Mediated with MOF Derived High Density Defective Metal Oxides

Guo

Zhao

Yuan

et al. 2020

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“…In literature, the observed O 1s peaks around 530 eV in CeO 2-x are typically ascribed to three oxygen species: lattice oxygen; oxygen vacancy; and surface-chem- isorbed oxygen species or oxygen in hydroxyl groups. [38,39] Due to the high concentration of surface oxygen vacancy, [24] the peaks at 529.3 and 531.4 eV are assigned to lattice oxygen (O L ) and oxygen vacancy/defects (O V ) on the surface of CeO 2 NR, respectively. The relative concentration of O v is calculated by the integrated peak area ratio of O species…”

Section: Chemical and Catalytic Propertiesmentioning

confidence: 99%

NaBH₄ Surface Modification on CeO₂ Nanorods Supported Transition‐Metal Catalysts for Low Temperature CO Oxidation

2020

Self Cite

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In this report, CeO2 nanorods (CeO2NR) were first chemically etched by different amounts (0.6, 3 and 6 wt %) of NaBH4, which were employed to understand the etching effect on the support structure, surface defects, and reducibility of modified CeO2NR supports. The 6 wt % NaBH4 etched CeO2NR was further used as support materials to load transition‐metals (TM: Cu, Co, Ni, Fe and Mn) catalysts, in order to investigate the support etching effect on the reducibility and catalytic performance of CeO2NR supported TM catalysts. In comparison with the catalytic performance of CeO2NR supported TM catalysts in literature, the 6 wt % NaBH4 etched CeO2NR supported catalysts show clearly enhanced CO oxidation performance at lower temperature, which is mainly attributed to the created surface defects by boron doped CeO2 surface during NaBH4 chemical etching and strong metal‐support interaction.

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Separated Active Site and Reaction Space for Multi‐Pollutant Elimination Significantly Enhancing Low Toxic Product Selectivity

Wei

Liu

Cui

et al. 2023

Adv Funct Materials

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It is possible to remove volatile organic compounds containing chlorine (CVOCs, such as chlorobenzene) in a single device designed for selective catalytic reduction of NOx with NH3 for the industries containing CVOCs and NOx. Breaking the efficiency‐selectivity trade‐off in chlorobenzene oxidation remains a major challenge due to the conjugation of halogen atoms with the benzene ring and the reducing nature of NH3. A stepwise synthesis strategy is demontrated to disperse dual Ru/Cu Lewis acid sites outside and inside the zeolite channel. Under the confinement of zeolite, the Ru4+ Lewis acid site on the external surface of the zeolite promotes chlorobenzene oxidation by weakening the p‐π conjugate structure of Cl and benzene ring, while the Cu2+ Lewis acid site within the internal channel converts NOx and NH3 to N2. The mutual interference between catalytic oxidation and reduction is successfully avoided. Therefore, the low toxic CO2 and HCl selectivity experience a considerable increase from 21% to 86%, and from 51% to 94% with 91% conversion of chlorobenzene, while maintaining excellent elimination performance for NO (with N2 selectivity exceeding 90%). The incorporation of separated active sites and reaction spaces into the design may offer potentials for other energy and environmental applications.

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Distribution and Valence State of Ru Species on CeO₂ Supports: Support Shape Effect and Its Influence on CO Oxidation

Cited by 186 publications

References 90 publications

Ultrafast Laser Manufacture of Stable, Efficient Ultrafine Noble Metal Catalysts Mediated with MOF Derived High Density Defective Metal Oxides

Ultrafast Laser Manufacture of Stable, Efficient Ultrafine Noble Metal Catalysts Mediated with MOF Derived High Density Defective Metal Oxides

NaBH₄ Surface Modification on CeO₂ Nanorods Supported Transition‐Metal Catalysts for Low Temperature CO Oxidation

Separated Active Site and Reaction Space for Multi‐Pollutant Elimination Significantly Enhancing Low Toxic Product Selectivity

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Distribution and Valence State of Ru Species on CeO2 Supports: Support Shape Effect and Its Influence on CO Oxidation

Cited by 186 publications

References 90 publications

Ultrafast Laser Manufacture of Stable, Efficient Ultrafine Noble Metal Catalysts Mediated with MOF Derived High Density Defective Metal Oxides

Ultrafast Laser Manufacture of Stable, Efficient Ultrafine Noble Metal Catalysts Mediated with MOF Derived High Density Defective Metal Oxides

NaBH4 Surface Modification on CeO2 Nanorods Supported Transition‐Metal Catalysts for Low Temperature CO Oxidation

Separated Active Site and Reaction Space for Multi‐Pollutant Elimination Significantly Enhancing Low Toxic Product Selectivity

Contact Info

Product

Resources

About

Distribution and Valence State of Ru Species on CeO₂ Supports: Support Shape Effect and Its Influence on CO Oxidation

NaBH₄ Surface Modification on CeO₂ Nanorods Supported Transition‐Metal Catalysts for Low Temperature CO Oxidation