...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Effect of water density on methanol oxidation kinetics in supercritical water
【24h】

Effect of water density on methanol oxidation kinetics in supercritical water

机译：水密度对超临界水中甲醇氧化动力学的影响

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We oxidized methanol in supercritical water at 500 degrees C to explore the influence of the water concentration (or density) on the kinetics. The rate increased as the water concentration increased from 1.8 to 5.7 mol/L. This effect of water density on the kinetics observed experimentally was quantitatively reproduced by a previously validated mechanism-based, detailed chemical kinetics model. In this model, reactions of OH radicals with methanol were the fastest methanol removal steps. The rates of these removal steps increased with water density at 500 degrees C because the OH radical concentration increased. The OH radical concentration increased with density because the rates of the steps H + H2O = OH + H-2 and CH3 + H2O = OH + CH4, which produce OH radicals, increased. Thus, the main role of water in accelerating methanol oxidation kinetics at 500 degrees C is as a hydrogen donor to a radical (R) in steps such as R + H2O = OH + RH. This system provides a striking example of SCW being involved on the molecular level in the free-radical oxidation as a reactant in elementary steps.
机译：我们在500摄氏度的超临界水中氧化了甲醇，以探索水浓度（或密度）对动力学的影响。随着水浓度从1.8 mol / L增加到5.7 mol / L，速率增加。通过先前验证的基于机理的详细化学动力学模型，定量地再现了水密度对实验观察到的动力学的影响。在此模型中，OH自由基与甲醇的反应是最快的甲醇去除步骤。这些去除步骤的速率随着500摄氏度水密度的增加而增加，因为OH自由基浓度增加了。 OH自由基浓度随密度增加而增加，因为产生OH自由基的步骤H + H2O = OH + H-2和CH3 + H2O = OH + CH4的速率增加。因此，水在500摄氏度下加速甲醇氧化动力学的主要作用是作为自由基（R）的氢供体，例如R + H2O = OH + RH。该系统提供了一个惊人的例子，表明SCW在基本步骤中作为反应物参与了自由基氧化的分子水平。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号