التفاصيل البيبلوغرافية
| العنوان: |
Detrimental role of residual surface acid ions on ozone decomposition over Ce-modified gamma-MnO2 under humid conditions |
| المؤلفون: |
Li, Xiaotong, Ma, Jinzhu, Zhang, Changbin, Zhang, Runduo, He, Hong |
| سنة النشر: |
2020 |
| المجموعة: |
Research Center for Eco-Environmental Sciences: RCEES OpenIR (Chinese Academy of Sciences) / 中国科学院生态环境研究中心机构知识库 |
| مصطلحات موضوعية: |
Ozone decomposition, Manganese dioxide, Surface acid ions, Moisture-resistant property, Oxygen vacancy |
| الوصف: |
In the study, the catalyst precursors of Ce-modified gamma-MnO2 were washed with deionized water until the pH value of the supernatant was 1, 2, 4 and 7, and the obtained catalysts were named accordingly. Under space velocity of 300,000 hr(-1), the ozone conversion over the pH = 7 catalyst under dry conditions and relative humidity of 65% over a period of 6 hr was 100% and 96%, respectively. However, the ozone decomposition activity of the pH = 2 and 4 catalysts distinctly decreased under relative humidity of 65% compared to that under dry conditions. Detailed physical and chemical characterization demonstrated that the residual sulfate ions on the pH = 2 and 4 catalysts decreased their hydrophobicity and then restrained humid ozone decomposition activity. The pH = 2 and 4 catalysts had inferior resistance to high space velocity under dry conditions, because the residual sulfate ion on their surface reduced their adsorption capacity for ozone molecules and increased their apparent activation energies, which was proved by temperature programmed desorption of O-2 and kinetic experiments. Long-term activity testing, X-ray photoelectron spectroscopy and density functional theory calculations revealed that there were two kinds of oxygen vacancies on the manganese dioxide catalysts, one of which more easily adsorbed oxygen species and then became deactivated. This study revealed the detrimental effect of surface acid ions on the activity of catalysts under humid and dry atmospheres, and provided guidance for the development of highly efficient catalysts for ozone decomposition. (C) 2020 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. |
| نوع الوثيقة: |
report |
| اللغة: |
unknown |
| Relation: |
JOURNAL OF ENVIRONMENTAL SCIENCES; http://ir.rcees.ac.cn/handle/311016/45070 |
| الاتاحة: |
http://ir.rcees.ac.cn/handle/311016/45070 |
| Rights: |
cn.org.cspace.api.content.CopyrightPolicy@2c619739 |
| رقم الانضمام: |
edsbas.F3D483DC |
| قاعدة البيانات: |
BASE |