Atomic layer deposition of platinum clusters on titania nanoparticles at atmospheric pressure

Goulas, Aristeidis; Ommen, J. Ruud van

doi:10.1039/c3ta01665j

Cited by 71 publications

(81 citation statements)

References 33 publications

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“…13 However, vacuum conveying would also be possible. 37 Operation under vacuum conditions is often preferred to facilitate a higher concentration of the precursors under the selected vaporization temperature conditions.…”

Section: Methodsmentioning

confidence: 99%

“…It has been demonstrated that batch-wise ALD on nanoparticles works very well in a fluidized bed. 3,13 During fluidization, the nanoparticles form agglomerates with a very open, fractal nature enabling a good access of precursors to the surface. [34][35][36] In temporal ALD, this has led to a very good dispersion of deposited material over the particles.…”

Section: Introductionmentioning

confidence: 99%

“…However, for applications in catalysis, it is typically undesirable to obtain a continuous film: the island structure should be maintained to maximize the dispersion. [11][12][13] For most practical catalytic applications, particles are used as support material. The deposition of materials on a particulate support via ALD was already proposed in the 1960s in the former Soviet Union.…”

Section: Introductionmentioning

confidence: 99%

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Continuous production of nanostructured particles using spatial atomic layer deposition

Ommen¹,

Kooijman²,

Niet³

et al. 2015

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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In this paper, the authors demonstrate a novel spatial atomic layer deposition (ALD) process based on pneumatic transport of nanoparticle agglomerates. Nanoclusters of platinum (Pt) of $1 nm diameter are deposited onto titania (TiO 2 ) P25 nanoparticles resulting to a continuous production of an active photocatalyst (0.12-0.31 wt. % of Pt) at a rate of about 1 g min À1 . Tuning the precursor injection velocity (10-40 m s À1 ) enhances the contact between the precursor and the pneumatically transported support flows. Decreasing the chemisorption temperature (from 250 to 100 C) results in more uniform distribution of the Pt nanoclusters as it decreases the reaction rate as compared to the rate of diffusion into the nanoparticle agglomerates. Utilizing this photocatalyst in the oxidation reaction of Acid Blue 9 showed a factor of five increase of the photocatalytic activity compared to the native P25 nanoparticles. The use of spatial particle ALD can be further expanded to deposition of nanoclusters on porous, micron-sized particles and to the production of core-shell nanoparticles enabling the robust and scalable manufacturing of nanostructured powders for catalysis and other applications.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Continuous production of nanostructured particles using spatial atomic layer deposition

Ommen¹,

Kooijman²,

Niet³

et al. 2015

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

Self Cite

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show abstract

“…The deposition scheme involves the sequential exposure of the support material to MeCpPtMe 3 and ozone (Goulas and van Ommen, 2013) at 250°C. The ALD reaction proceeds via a mechanism proposed by Kessels et al (2009) adapted to the following generic scheme:…”

Section: Methodsmentioning

confidence: 99%

“…Recently, the atmospheric pressure operation of a fluidized bed ALD reactor was demonstrated for the growth of thin films (Beetstra et al, 2009) and the deposition of highly-dispersed nanoparticles (Goulas and van Ommen, 2013). Although the pulsing times required are longer than the equivalent in low-pressure operation, the process was proven to be efficient in terms of precursor utilization while excluding the need for expensive vacuum equipment.…”

Section: Reactor Technologymentioning

confidence: 99%

Scalable Production of Nanostructured Particles using Atomic Layer Deposition

Goulas

Ommen

2014

KONA

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Core-shell nanoparticles and other nanostructured particles have high potential in applications such as heterogeneous catalysis and energy conversion and storage. However, a hurdle in their utilization is that typically, large amounts of such nanostructured materials are required. Gas-phase coating using atomic layer deposition (ALD, a variant of chemical vapour deposition) can be used to provide the surface of a particle with either an ultrathin continuous coating or a decoration of nanoclusters. When carried out in a fluidized bed, ALD is an attractive way of producing nanostructured particles with excellent scale-up potential. We demonstrate the fabrication of catalysts by deposition of the active phase (Pt) on fluidized nanoparticles (TiO 2 P25) at atmospheric pressure. We show that ALD is a technique that 1) guarantees efficient use of the precursor; 2) allows precise control of the size and loading; 3) can be used for low and medium loading of catalysts by adjusting the number of repeated cycles; 4) leads to high-quality (low impurities level) end-products.

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