Ozone decomposition over manganese oxide supported on ZrO2 and TiO2: a kinetic study using in situ laser Raman spectroscopy
Ozone decomposition over manganese oxide supported on ZrO2 and TiO2: a kinetic study using in situ laser Raman spectroscopy
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DOI：
10.1006/jcat.2001.3167
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发表时间：
2001-04
影响因子：
7.3
通讯作者：
R. Radhakrishnan;S. Oyama
中科院分区：
文献类型：
--
作者：
R. Radhakrishnan;S. Oyama
摘要利用原位激光拉曼光谱沿着稳态动力学研究了臭氧在氧化锆和二氧化钛负载的氧化锰上的分解。的拉曼光谱表明，在反应条件下的两种催化剂的吸附的过氧化物物种的存在下。实验数据很好地代表了一个不均匀的表面动力学处理，假设吸附和解吸的活化能是过氧化物物种的表面覆盖度的线性函数。在不同的臭氧分压（0.6-3 kPa）和温度（293-343 K）下监测稳态反应速率。相对于臭氧分压的ZrO 2负载的样品的反应级数为0.98，而对于TiO 2负载的样品的反应级数为0.85。在零表面覆盖度的过氧化物物种，吸附活化能为6和7 kJ/mol的ZrO 2和TiO 2负载的催化剂，分别。对于相同的催化剂，在零覆盖率下的脱附活化能分别为62和44 kJ/mol。催化剂的臭氧分解活性的差异主要是由于脱附动力学参数的差异。
Abstract Ozone decomposition on ZrO 2 - and TiO 2 -supported manganese oxide was studied using in situ laser Raman spectroscopy along with simultaneous steady-state kinetic measurements. The Raman spectra showed the presence of an adsorbed peroxide species for both catalysts under reaction conditions. The experimental data were well represented by a nonuniform surface kinetic treatment that assumed that the activation energies of adsorption and desorption were linear functions of the surface coverage of the peroxide species. Steady-state reaction rates were monitored for varying ozone partial pressure (0.6–3 kPa) and temperature (293–343 K). The reaction order with respect to ozone partial pressure for the ZrO 2 -supported sample was 0.98 and that for the TiO 2 -supported sample was 0.85. At zero surface coverage of the peroxide species, the activation energy for adsorption was 6 and 7 kJ/mol for the ZrO 2 - and TiO 2 -supported catalysts, respectively. The activation energies for desorption at zero coverage were 62 and 44 kJ/mol, respectively, for the same catalysts. The difference in ozone decomposition activity for the catalysts was primarily due to the difference in desorption kinetic parameters.