Operando and Kinetic Study of Low-Temperature, Lean-Burn Methane Combustion over a Pd/纬-Al2O3 Catalyst

详细信息    查看全文

• 作者：Jing Xu ; Like Ouyang ; Wei Mao ; Xue-Jing Yang ; Xin-Chao Xu ; Jun-Jie Su ; Ting-Zhou Zhuang ; Hui Li ; Yi-Fan Han
• 刊名：ACS Catalysis
• 出版年：2012
• 出版时间：February 3, 2012
• 年：2012
• 卷：2
• 期：2
• 页码：261-269
• 全文大小：422K
• 年卷期：v.2,no.2(February 3, 2012)
• ISSN：2155-5435

文摘

Operando and kinetic studies of lean-burn methane combustion were preformed on a Pd(3.3 wt %)/纬-Al₂O₃ catalyst in a low temperature range of 473鈥?73 K. The reaction order with respect to oxygen decreased with temperature, and the order with respect to methane remained constant. The working catalyst is characterized using operando Raman spectroscopy and in situ diffuse reflectance infrared Fourier transform spectroscopy of CO adsorption (DRIFTS), and the Pd chemical states were measured with X-ray photoelectron spectroscopy (XPS). Partial oxidation of Pd atoms during reaction was identified by Raman and XPS spectroscopies. In particular, the DRIFT spectra revealed that 45% of Pd atoms at the top layers were transferred into PdO_x species above 523 K. The reaction was assumed to occur primarily on the metallic Pd sites below 673 K, proceeding through the Langmuir鈥揌inshelwood mechanism, and Pd oxide may affect the adsorption and activation of reactants.

Keywords:

kinetics; low-temperature methane combustion; operando spectroscopy; Raman; in situ DRIFTS; Pd/纬-Al₂O₃; catalyst