...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Catalysis science & technology >Hydrodeoxygenation of propanoic acid over silica-supported palladium: effect of metal particle size
【24h】

Hydrodeoxygenation of propanoic acid over silica-supported palladium: effect of metal particle size

机译：硅酸在硅胶钯上的丙酸丙酸的加氢氧合：金属粒径的影响

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

The effects of metal nanoparticle size on the hydrodeoxygenation (HDO) of propanoic acid (PAc) over Pd/SiO2 catalysts was investigated. Strong electrostatic adsorption (SEA) was used to prepare catalysts with Pd nanoparticles ranging between 1.9 to 12.4 nm. The particle sizes were determined by chemisorption (O2-H2 titration) and scanning transmission electron microscopy (STEM). The HDO was carried out in a continuous gas-phase reactor at 200 °C and 1 atm at differential conversion. The reaction followed decarbonylation and hydrogenation pathways to yield ethane (C2H6) and propionaldehyde (EtCHO), respectively. While the catalytic TOF remained constant between 3.0-12.4 nm, it decreased by a factor of 2-3 with decreasing particle size down to 1.9 nm. The reaction rate is therefore considered to be largely structure-insensitive over the range studied. The selectivity toward EtCHO increased as the particle size increased, indicating hydrogenation is favored on single crystal Pd(111) and Pd(100) planes versus corners and edges. For decarbonylation to produce C2H6, reaction rate orders with respect to PAc (~0.5) and H2 (～0), and the apparent activation energy (～12 kcal per mole), were found to be the same for both 2.0 and 12.4 nm particle sizes, in contrast, the reaction rate order with respect to PAc (～1.0) and H2 (～0.3) was different for hydrogenation to produce EtCHO. These differences are explained by a change in the rate-determining step for the HDO of propanoic acid.
机译：研究了金属纳米颗粒大小对丙酸丙酸（PAC）的氢氧合（HDO）对PD/SIO2催化剂的影响。强烈的静电吸附（SEA）用于制备PD纳米颗粒范围为1.9至12.4 nm的催化剂。通过化学吸附（O2-H2滴定）和扫描透射电子显微镜（STEM）确定粒径。 HDO是在200°C的连续气相反应器中进行的，在差分转化时进行1个atm。该反应分别遵循脱蜡和氢化途径，分别产生乙烷（C2H6）和丙醛（Etcho）。虽然催化性TOF保持在3.0-12.4 nm之间的恒定，但随着粒径降低至1.9 nm，它降低了2-3倍。因此，在研究范围内，该反应速率在很大程度上对结构不敏感。随着粒径的增加，对蚀刻的选择性增加，表明在单晶PD（111）和PD（100）平面对氢而相对于角和边缘方面有利于氢化。为了产生C2H6的脱轴偶像化，发现相对于PAC（〜0.5）和H2（～0）的反应速率顺序，并且发现2.0和12.4 nm粒子的表观激活能（每摩尔12 kcal）相同相比之下，大小相对于PAC（～1.0）和H2（～0.3）的反应速率顺序对于产生蚀刻的氢化是不同的。这些差异是通过丙酸HDO的速率确定步骤的变化来解释的。

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