• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>RSC Advances >Biosynthesized Ag/α-Al2O3 catalyst for ethylene epoxidation: the influence of silver precursors
【24h】

Biosynthesized Ag/α-Al2O3 catalyst for ethylene epoxidation: the influence of silver precursors

机译：乙烯环氧化的Biosynthesized Ag /α-Al2O3催化剂：银前体的影响

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Biosynthesized Ag/α-Al _(2) O _(3) catalysts toward ethylene epoxidation were prepared with Cinnamomum camphoratrees (CC) extract using AgNO _(3) , silver–ammonia complex ([Ag (NH _(3) ) _(2) ] ~(+) ) and silver–ethylenediamine complex ([Ag(en) _(2) ] ~(+) ) as the silver precursors. The catalyst from [Ag(en) _(2) ] ~(+) demonstrated better activity compared to the catalysts from the other two precursors, 1.41% EO concentration with EO selectivity of 79.1% and 12.0% ethylene conversion were achieved at 250 °C. To investigate the influence of silver precursors on the catalytic performance, three catalysts were characterized by XRD, UV-Vis, XPS, SEM and O _(2) -TPD techniques. The results indicated that [Ag(en) _(2) ] ~(+) precursors could be reduced more effectively by CC extract, and Ag particles were successfully immobilized onto the α-Al _(2) O _(3) support under mild conditions. Moreover, a silver defects surface on the Ag/α-Al _(2) O _(3) catalyst from [Ag(en) _(2) ] ~(+) precursors had the best oxygen activation ability, playing an important role in the generation of electrophilic oxygen species which were responsible for the epoxidation reaction of CC to EO.
机译：使用AgNO _（3），银氨络合物（[Ag（NH _（3））_用肉桂瘤（CC）提取物，制备生物细胞氧化乙烯环氧化催化剂的乙烯环氧化催化剂（CC）提取物（2）]〜（+））和银 - 乙二胺络合物（[Ag（烯）_（2）]〜（+））作为银前体。与来自其他两个前体的催化剂相比，来自[Ag（Zh）_（2）]〜（+）的催化剂表明了更好的活性，EO选择性为1.41％的EO浓度为79.1％和12.0％乙烯转化率为250° C。为了研究银前体对催化性能的影响，通过XRD，UV-Vis，XPS，SEM和O _（2）-TPD技术以三种催化剂为特征。结果表明，通过CC提取物更有效地减少[Ag（Zh）_（2）]〜（+）前体，Ag颗粒成功地固定在α-Al _（2）O _（3）支撑下温和的条件。此外，Ag /α-Al _（2）O _（3）催化剂上的银缺陷表面来自[Ag（Zh）_（2）]〜（+）前体具有最佳的氧激活能力，发挥重要作用在发电的电子亲电氧物质中，该氧对CC对EO的环氧化反应负责。

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