Low temperature CO pulse adsorption for the determination of Pt particle size in a Pt/Cerium-based oxide catalyst
Low temperature CO pulse adsorption for the determination of Pt particle size in a Pt/Cerium-based oxide catalyst
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DOI：
10.1016/j.apcata.2009.09.030
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发表时间：
2009-11
影响因子：
5.5
通讯作者：
Toshitaka Tanabe;Y. Nagai;T. Hirabayashi;N. Takagi;K. Dohmae;Naoki Takahashi;Matsumoto Shinichi;H. Shinjoh;J. Kondo;J. J. Schouten-J.;H. Brongersma
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文献类型：
--
作者：
Toshitaka Tanabe;Y. Nagai;T. Hirabayashi;N. Takagi;K. Dohmae;Naoki Takahashi;Matsumoto Shinichi;H. Shinjoh;J. Kondo;J. J. Schouten-J.;H. Brongersma
在323 K下的脉冲吸附实验中，出乎意料地产生了大量的CO吸附，在Pt/铈基氧化物催化剂中得到约300%的Pt分散体。原位漫反射红外傅里叶变换光谱研究Pt/铈基氧化物在CO吸附过程中发现，在氧化铈表面上的碳酸盐物种负责不切实际的大CO吸附在323 K，作为CO溢出的结果。将温度降低到195 K大大减少了CO吸附量。在195 K下用CO脉冲吸附法测定了Pt/铈基氧化物催化剂中Pt颗粒的尺寸，并与X射线衍射法和低能离子散射法测定的颗粒尺寸一致。这表明在195 K下的CO脉冲吸附是可靠地估计Pt/铈基氧化物催化剂中的Pt颗粒尺寸的有用技术。
Unexpectedly large amounts of CO adsorption have resulted from a pulse adsorption experiment at 323K, 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 323K, as a result of CO spillover. Lowering the temperature to 195K 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 195K 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 195K is a useful technique to reliably estimate the Pt particle size in a Pt/cerium-based oxide catalyst.