Low-temperature atomic layer deposition delivers more active and stable Pt-based catalysts

Abstract

We tailored the size distribution of Pt nanoparticles (NPs) on graphene nanoplatelets at a given metal loading by using low-temperature atomic layer deposition carried out in a fluidized bed reactor operated at atmospheric pressure. The Pt NPs deposited at low temperature (100°C) after 10 cycles were more active and stable towards the propene oxidation reaction than their high-temperature counterparts.Crucially, the gap in the catalytic performance was retained even after prolonged periods of time (>24 hours) at reaction temperatures as high as 450°C. After exposure to such harsh conditions the Pt NPs deposited at 100°C still retained a size distribution that is narrower than the one of the assynthesized NPs obtained at 250°C. The difference in performance correlated with the difference in the number of facet sites as estimated after the catalytic test. Our approach provides not only a viable route for the scalable synthesis of stable supported Pt NPs with tailored size distributions but also a tool for studying the structure-function relationship.

Carbon Nanotubes Decorated with Platinum Nanoparticles for Field-Emission Application

“…Such a wide size distribution of Pt NPs deposited with a low cycle number (∼25 cycles) was reported previously and the following explanation was provided. 19,20 There existed two growth regimes for Pt ALD, one at low temperatures (i.e., T ≤ 100 °C) and one at high temperatures (i.e., T ≥ 150 °C). The high temperature regime is characterized by the formation of large NPs aside of small ones and very broad distribution of the interparticle distances.…”

Thermal atomic layer deposition of gold nanoparticles: controlled growth and size selection for photocatalysis

“…This is because practical applications often require large amounts of material, and fabricating supported nanoparticles with a controlled size in a scalable fashion remains challenging. [14][15][16] Conventional techniques for the synthesis of supported Au nanoparticles typically rely on liquid-phase processes. [17][18][19][20] While these methods have been extensively studied and optimized, their practical applicability still faces some challenges.…”

“…Atomic layer deposition (ALD) is a vapor-phase deposition technique for the synthesis of supported nanoparticles as it boasts high precursor utilization efficiency, low degree of contamination of the final product, and an excellent degree of control over both the metal loading and the particle size. 16,[23][24][25][26][27][28][29] While there exist over seventy ALD processes for the deposition of noble metals, only limited success with regards to Au has been reported. 10 Two successful studies on ALD of Au include a plasma process at 120°C using (trimethylphosphino)trimethylgold(III) as metal precursor; and a thermal process at 180°C, with dimethylgold(III)(diethylthiocarbamato) as metal precursor.…”

Thermal Atomic Layer Deposition of Gold Nanoparticles: Controlled Growth and Size Selection for Photocatalysis

“…Atomic layer deposition (ALD) is a vapor-phase deposition technique that is emerging as a promising method for the synthesis of supported nanoparticles as it boasts high precursor utilization efficiency, low degree of contamination of the final product, and an excellent degree of control over both the metal loading and the particle size [16,[23][24][25][26][27][28][29]. While there exist over seventy ALD processes for the deposition of noble metals, only limited success with regards to Au has been reported [1].…”