Ultrastable Au nanoparticles on titania through an encapsulation strategy under oxidative atmosphere

Liu, Shaofeng; Xu, Wei; Niu, Yiming; Zhang, Bingsen; Zheng, Lirong; Liu, Wei; Li, Lin; Wang, Junhu

doi:10.1038/s41467-019-13755-5

Cited by 152 publications

(131 citation statements)

References 64 publications

Supporting

Mentioning

118

Contrasting

Order By: Relevance

“…Au/TiO 2 has been reported to have a lower resonance intensity than Au particles of a similar size in the absence of strong interaction with surface capping molecules 46 . The metal-support interaction results in a negative charge injection into the metal particles by reducible oxides, and a higher increase in d -electron density at the gold site compared to bare Au nanoparticles 47 . The number of unoccupied Au 5 d 5/2 states near the Fermi level is depleted.…”

Section: Resultsmentioning

confidence: 99%

Gold catalysts containing interstitial carbon atoms boost hydrogenation activity

et al. 2020

Self Cite

View full text Add to dashboard Cite

Supported gold nanoparticles are emerging catalysts for heterogeneous catalytic reactions, including selective hydrogenation. The traditionally used supports such as silica do not favor the heterolytic dissociation of hydrogen on the surface of gold, thus limiting its hydrogenation activity. Here we use gold catalyst particles partially embedded in the pore walls of mesoporous carbon with carbon atoms occupying interstitial sites in the gold lattice. This catalyst allows improved electron transfer from carbon to gold and, when used for the chemoselective hydrogenation of 3-nitrostyrene, gives a three times higher turn-over frequency (TOF) than that for the well-established Au/TiO2 system. The d electron gain of Au is linearly related to the activation entropy and TOF. The catalyst is stable, and can be recycled ten times with negligible loss of both reaction rate and overall conversion. This strategy paves the way for optimizing noble metal catalysts to give an enhanced hydrogenation catalytic performance.

show abstract

Section: Resultsmentioning

confidence: 99%

Gold catalysts containing interstitial carbon atoms boost hydrogenation activity

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Tuning the strong metal‐support interactions (SMSIs) between the metal catalyst and oxide support is considered an effective strategy for enhancing catalytic selectivity and stability. [ 2–6 ] There are multiple categories of SMSIs, including metal‐support charge transfer, metal‐support interphase layer formation, and the encapsulation metal‐support interaction, among others. [ 7 ] In particular, the encapsulation interaction shows promise as a potential mechanism for immobilizing oxide‐supported nanoparticle catalysts and controlling their selectivity.…”

Section: Introductionmentioning

confidence: 99%

Machine Learning Method Reveals Hidden Strong Metal‐Support Interaction in Microscopy Datasets

et al. 2021

View full text Add to dashboard Cite

Forming an ultra‐thin, permeable encapsulation oxide‐support layer on a metal catalyst surface is considered an effective strategy for achieving a balance between high stability and high activity in heterogenous catalysts. The success of such a design relies not only on the thickness, ideally one to two atomic layers thick, but also on the morphology and chemistry of the encapsulation layer. Reliably identifying the presence and chemical nature of such a trace layer has been challenging. Electron energy‐loss spectroscopy (EELS) performed in a scanning transmission electron microscope (STEM), the primary technique utilized for such studies, is limited by a weak signal on overlayers when using conventional analysis methods, often leading to misinterpreted or missed information. Here, a robust, unsupervised machine learning data analysis method is developed to reveal trace encapsulation layers that are otherwise overlooked in STEM‐EELS datasets. This method provides a reliable tool for analyzing encapsulation of catalysts and is generally applicable to any spectroscopic analysis of materials and devices where revealing a trace signal and its spatial distribution is challenging.

show abstract

“…TiOx encapsulation can be identified using scanning tunneling microscopy (STM) and/or low energy electron diffraction (LEED) by the observation of moiré superstructures between the TiOx overlayer and the metal surface, usually on Pd(111) [2,4,13] and Pt(111) surfaces [3,8,9]. In contrast to the relatively easily observed encapsulation on the outer surface of metal particles, only a few studies have conjectured that the metal-oxide support interface was also modified during SMSI [14,15]. It has also been reported that no change in the crystal structure was observed for the Pd-TiO2 interface when encapsulation occurred [16], although this study strictly speaking only confirms that the interface was not changed to the extent that the crystallography or epitaxial orientation was affected.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamics driving the strong metal–support interaction: Titanate encapsulation of supported Pd nanocrystals

Chen

Gao

Castell

2021

Phys. Rev. Materials

View full text Add to dashboard Cite

The strong metal-support interaction (SMSI) is the encapsulation of a supported metal particle by an oxide layer that diffuses from the substrate. This process is usually described as being driven by a reduction in the surface energy of the metal particle and has a significant influence on the catalytic activity of the metal. Here, epitaxial Pd nanocrystals grown in ultrahigh vacuum on SrTiO3(001) and anatase TiO2(001) substrates are studied by scanning tunneling microscopy. At annealing temperatures above ~600 ºC, the Pd crystals can become encapsulated by a TiOx monolayer originating from the substrates. For both bare and encapsulated Pd crystals, their height-to-width ratio increases with the crystal height as a mechanism to partially release their interfacial misfit strain with the substrate.However, the rate of this increase is lower for encapsulated crystals, indicating that during the SMSI process the interface between the particle and the oxide is modified to form a lower energy interfacial structure which also results in less strain in the encapsulated particle. The SMSI is found to preferentially occur on larger crystals, driven by the reduction in their elastic strain energy, which scales with the crystal volume. Compared with the traditional view of SMSI our results provide a more complete description of the encapsulation process.

show abstract

Ultrastable Au nanoparticles on titania through an encapsulation strategy under oxidative atmosphere

Cited by 152 publications

References 64 publications

Gold catalysts containing interstitial carbon atoms boost hydrogenation activity

Gold catalysts containing interstitial carbon atoms boost hydrogenation activity

Machine Learning Method Reveals Hidden Strong Metal‐Support Interaction in Microscopy Datasets

Thermodynamics driving the strong metal–support interaction: Titanate encapsulation of supported Pd nanocrystals

Contact Info

Product

Resources

About