Metal-Support Interaction of Pt Nanoparticles with Ionically and Non-Ionically Conductive Supports for CO Oxidation

Abstract

AIR+HDO:ESO:LLI:PVEPlatinum nanoparticles of narrow size distribution (similar to 2.5 nm) were synthesized using a modified polyol method and deposited on yttria-stabilized zirconia (Pt/YSZ), carbon (Pt/C) and gamma-alumina (Pt/gamma-Al2O3) supports, resulting in 1 wt % of Pt loading. Pt/YSZ has the highest catalytic activity toward CO oxidation among the studied catalysts. Decrease in the average particle size of Pt/YSZ led to the increase in CO conversion at low temperatures. Enhanced performances can be explained by the thermally induced O2- backspillover from YSZ over Pt nanoparticles in agreement with the electrochemical promotion mechanism. Observed effect becomes more pronounced with decreasing the particle size. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.024203esl] All rights reserved

Promotion of Pt Nanoparticles by Lattice Oxygen in SmFeO3 Perovskite Group for Carbon Monoxide and Ethylene Oxidation

“…Therefore, similarly to the catalytic activity of bare supports, the activity of Pt NPs-loaded perovskites is optimal at x = 0.05 for CO and x = 0.01 for C 2 H 4 oxidations. The ionically conductive YSZ support showed inferior activity to SCF-1 and SCF-5 for both reactions, however outperformed the conventional non-conductive c-Al 2 O 3 support, in agreement with previous works [32,53]. It is important to emphasize that among all the supports, alumina has the largest specific surface area and the highest Pt dispersion, while the perovskites possess quite low specific surface area and NPs dispersion, with the smallest values corresponding to Pt/SCF-1.…”

“…Figure 4 shows the representative light-off curves for CO and C 2 H 4 conversion over Pt/SCF-5 and Pt/SCF-1 as a function of temperature for three consecutive runs. The performance of all catalysts is stable after the first cycle because the second and third cycles are similar, indicating that Pt nanoparticles remain free of sintering or deactivation, in agreement with recent works on supported Pt NPs [26,32,53]. Figure 5 shows the reaction rate per catalyst active surface area (Table 1) and TOF, whereas Fig.…”

“…Synthesis of Pt nanoparticles was carried out using a polyol reduction method described earlier [31,32]. In short, Top Catal 0.2334 g of PtCl 4 metal salt (Alfa Aesar, 99.9 % metals basis) was dissolved in 25 mL of ethylene glycol (anhydrous 99.8 % Sigma Aldrich) containing 0.08 M NaOH (EM Science, ACS grade).…”

Size-dependent activity of Pt/yttria-stabilized zirconia catalyst for ethylene and carbon monoxide oxidation in oxygen-free gas environment

“…4S in SI). Recently, it has been shown that YSZ support is able to oxidize VOC and soot at temperatures higher than 270°C in excess of molecular oxygen [12,14,19,20]. Similar to electrooxidation by O 2À , the oxidation of both CO and C 2 H 4 by gas-phase oxygen is particle-size dependent.…”

“…Thus, in the case of NPs dispersed on YSZ, the general phenomenon of metalsupport interaction (MSI) [10] is functionally identical to EPOC [5,[7][8][9]. Several recent studies demonstrated that YSZ can finely disperse and stabilize nanoparticles and strongly enhance the catalytic activity of metal or metal oxide nanostructured catalysts through the action of the thermally induced O 2À promoters [11][12][13][14], which makes it very promising support material in heterogeneous catalysis [11][12][13][14]. Recently, Vernoux and coworkers carried out isotopic studies of propane combustion on Pt nanoparticles supported on YSZ [15].…”