Active TiO2-Nanostructured Surfaces for CO Oxidation on Rh Model Catalysts at Low-Temperature

Camposeco, R.; Castillo, S.; Hinojosa-Reyes, Mariana; Zanella, Rodolfo; López-Curiel, Julio C.; Fuentes, Gustavo A.; Mejía‐Centeno, Isidro

doi:10.1007/s10562-019-02757-z

Cited by 7 publications

(5 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We did the assignment of the peaks in the spectra according to the literature (Figures S11 and S12 and Table S4). ,,− First of all, in the CO adsorption region of the spectra obtained in the CO-DRIFTS experiments (Figure S11), we did not observe the signal of CO adsorbed on metallic species (M 0 ) in the M-SA samples except for the signals of M n + ( n = 1, 2, 3, ...) and M δ+ (0 < δ < 1) under the CO atmosphere, suggesting that they were indeed SACs. With regard to the M-NC samples, we could find peaks of CO adsorbed on M 0 in addition to the metal species appeared in M-SA.…”

Section: Resultsmentioning

confidence: 80%

Tunable Electronic Metal–Support Interactions on Ceria-Supported Noble-Metal Nanocatalysts in Controlling the Low-Temperature CO Oxidation Activity

Yuan

Huang

et al. 2020

Inorg. Chem.

View full text Add to dashboard Cite

A fundamental study on the metal−support interactions of supported metal catalysts is of great importance for developing heterogeneous catalysts with high performance, is still attracting and challenging in many heterogeneous catalytic reactions. In this work, we report the catalytic performances of CeO 2 -supported noble-metal catalysts among single atoms, subnanoclusters (∼1 nm), and nanoparticles (2.2−2.7 nm) upon low-temperature CO oxidation reaction between 50 and 250 °C. The subnanoclusters and nanoparticles of Ru, Rh, and Ir showed much higher activities than those of the single atoms, while a Pd single-atom catalyst was more active than Pd subnanoclusters and nanoparticles. According to the results of multiple ex situ and in situ characterizations, the much different activities of Ru, Rh, Ir, and Pd were derived from the alterable electronic metal−support interactions (EMSI), which determine the concurrent reaction pathway including the famous Mars van Krevelen mechanism and carbonate−intermediate route on the most active metal sites of M δ+ (0 < δ < 1) for Ru, Rh, and Ir and Pd 2+ for Pd. Also, the moderate EMSI of CeO 2 -supported Rh subnanoclusters furthest benefited activation of the adsorbed CO molecule and ensured it the highest activity among CeO 2 -supported Ru, Rh, and Ir catalysts with similar metal deposit sizes.

show abstract

Section: Resultsmentioning

confidence: 80%

Tunable Electronic Metal–Support Interactions on Ceria-Supported Noble-Metal Nanocatalysts in Controlling the Low-Temperature CO Oxidation Activity

Yuan

Huang

et al. 2020

Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…BEs of Pd nanoparticles deposited on TiO 2 range from 334.6 to 335.5 eV. − These reported shifts in comparison to the value of bulk Pd might be ascribed to electronic metal–support interactions. Along this line, the shift to higher BE observed for L-titanate@Pd@L-titanate would indicate a slightly positively charged species of Pd δ+ (δ < 1). , A shift to higher BE of small metal nanoparticles can, however, also originate from final state effects or an ill-defined reference level. The BE of the two reference catalysts Pd ext @Al 2 O 3 and Pd ext @P25 were found at 335.1 and 335.3 eV, respectively.…”

Section: Resultsmentioning

confidence: 94%

“…The first is the need to balance the permanent negative layer charge of L-titanate nanosheets. Furthermore, an additional contribution might originate from electronic interactions between the metal and the oxide that were reported between noble metals and noncharged TiO 2 . , To probe the latter, the Ti 2p regions in the XPS of L-titanate@Pd@L-titanate and of H + -L-titanate before intercalation of the nanoparticles were compared (Figure a). The Ti 2p 3/2 signal of H + -L-titanate was found at a BE of 458.5 eV, which can be ascribed to Ti 4+ .…”

Section: Resultsmentioning

confidence: 99%

“…Along this line, the shift to higher BE observed for L-titanate@Pd@L-titanate would indicate a slightly positively charged species of Pd δ+ (δ < 1). 45,46 A shift to higher BE of small metal nanoparticles can, however, also originate from final state effects or an ill-defined reference level. The BE of the two reference catalysts Pd ext @ Al 2 O 3 and Pd ext @P25 were found at 335.1 and 335.3 eV, respectively.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Enhancing the Catalytic Activity of Palladium Nanoparticles via Sandwich-Like Confinement by Thin Titanate Nanosheets

et al. 2021

View full text Add to dashboard Cite

As atomically thin oxide layers deposited on flat (noble) metal surfaces have been proven to have a significant influence on the electronic structure and thus the catalytic activity of the metal, we sought to mimic this architecture at the bulk scale. This could be achieved by intercalating small positively charged Pd nanoparticles of size 3.8 nm into a nematic liquid crystalline phase of lepidocrocite-type layered titanate. Upon intercalation the galleries collapsed and Pd nanoparticles were captured in a sandwichlike mesoporous architecture showing good accessibility to Pd nanoparticles. On the basis of X-ray photoelectron spectroscopy (XPS) and CO diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) Pd was found to be in a partially oxidized state, while a reduced Ti species indicated an electronic interaction between nanoparticles and nanosheets. The close contact of titanate sandwiching Pd nanoparticles, moreover, allows for the donation of a lattice oxygen to the noble metal (inverse spillover). Due to the metal–support interactions of this peculiar support, the catalyst exhibited the oxidation of CO with a turnover frequency as high as 0.17 s–1 at a temperature of 100 °C.

show abstract

“…Therefore, extensive studies [4][5][6] have been conducted on the detailed process of CO oxidation to understand the relationship between CO oxidation activity and the morphology, the electronic properties of the catalyst, so as to design more efficient catalysts. Noble metals like Rh [7][8][9] and Pd [10][11][12] show excellent catalytic activities on converting CO to CO 2 , but the high prices and limited reserves, as well as the demand of high temperature for ideal efficiency impede their large-scale industrialization.…”

Section: Introductionmentioning

confidence: 99%

A theoretical study of the improved CO oxidation on WC supported Au monolayer by Cu doping

Chang¹,

Zhang²,

Yang³

2023

Phys. Scr.

View full text Add to dashboard Cite

Metal monolayer supported on tungsten carbides have received considerable attention in the field of catalysis, while the adsorption properties of reactants need to be optimized to improve the catalytic activity further. Alloy monolayers on tungsten carbides can deliver different geometric and electronic characters from pure metal layers, owing to the change in local environments. Herein, using the first-principles calculations, the CO oxidation processes on the supported CuAu alloy monolayer on tungsten carbide are systematically investigated and compared with that on pure metal monolayers. It is found that introducing Cu dopant in Au monolayer will elevate the d-band center of the formed alloy monolayer and thus enhancing the adsorption of reactants around the Cu atom, which is caused by the charge redistribution. Especially, the unbalanced interaction strength between Cu-O and Au-O promotes the rotation and migration of oxygen atom to interact with the C atom of CO, which lowers the energy barriers for the formation and dissociation of OOCO intermediate. The oxidation of CO by an atomic O with the largest energy barrier of 0.27 eV along the Langmuir-Hinshelwood pathway is identified as the rate determining step, which is superior or comparable to the reported CO oxidation catalysts. The significance of alloy monolayer on tungsten carbides are further highlighted by comparing the adsorption energy and reaction barrier of rate-limiting step on the pure metal monolayers. This work is insightful for the rational design of highly efficient catalysts based on alloy systems.

show abstract

Active TiO2-Nanostructured Surfaces for CO Oxidation on Rh Model Catalysts at Low-Temperature

Cited by 7 publications

References 51 publications

Tunable Electronic Metal–Support Interactions on Ceria-Supported Noble-Metal Nanocatalysts in Controlling the Low-Temperature CO Oxidation Activity

Tunable Electronic Metal–Support Interactions on Ceria-Supported Noble-Metal Nanocatalysts in Controlling the Low-Temperature CO Oxidation Activity

Enhancing the Catalytic Activity of Palladium Nanoparticles via Sandwich-Like Confinement by Thin Titanate Nanosheets

A theoretical study of the improved CO oxidation on WC supported Au monolayer by Cu doping

Contact Info

Product

Resources

About