Low temperature CO pulse adsorption for the determination of Pt particle size in a Pt/cerium-based oxide catalyst

• Published in: Applied catalysis. A, General Vol. 370; no. 1; pp. 108 - 113
• Main Authors: Tanabe, Toshitaka, Nagai, Yasutaka, Hirabayashi, Takeshi, Takagi, Nobuyuki, Dohmae, Kazuhiko, Takahashi, Naoki, Matsumoto, Shin’ichi, Shinjoh, Hirohumi, Kondo, Junko N., Schouten, Jaap C., Brongersma, Hidde H.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 30.11.2009; Elsevier
• Subjects: Adsorption; Carbon monoxide; Catalysis; Catalysts; Cerium-based oxide; Chemistry; CO adsorption; Dispersions; Exact sciences and technology; General and physical chemistry; Low energy ion scattering; Oxides; Particle size; Platinum; Pt particle size; Surface chemistry; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; X-ray diffraction; X-ray diffraction; Cerium-based oxide; Pt particle size; CO adsorption; Low energy ion scattering; Particle size; In situ; Pulse; Cerium oxide; X ray diffraction; Dispersion; Lanthanide compound; Particle; Heterogeneous catalysis; Spillover; Adsorption; Energy; Ion scattering; Carbonates; Catalyst; Low temperature; Reflectance
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2009.09.030

The Pt particle size in the Pt/cerium-based oxide catalyst was determined by CO pulse adsorption at 195 K and showed good agreement with the particle size determined by X-ray diffraction and low energy ion scattering. This indicates that CO pulse adsorption at 195 K is a useful technique to reliably estimate the Pt particle size. Unexpectedly large amounts of CO adsorption have resulted from a pulse adsorption experiment at 323 K, giving about 300% Pt dispersion in a Pt/cerium-based oxide catalyst. An in situ diffuse reflectance infrared Fourier transform spectroscopic investigation on a Pt/cerium-based oxide during CO adsorption has revealed that carbonate species on the cerium oxide surface are responsible for the unrealistically large CO adsorption at 323 K, as a result of CO spillover. Lowering the temperature to 195 K considerably diminished the amount of CO adsorption. The size of the Pt particles in the Pt/cerium-based oxide catalyst was determined by CO pulse adsorption at 195 K and showed good agreement with the particle size determined by X-ray diffraction and low energy ion scattering. This indicates that CO pulse adsorption at 195 K is a useful technique to reliably estimate the Pt particle size in a Pt/cerium-based oxide catalyst.