...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Catalysis science & technology >Temperature dependence of Cu-Al spinel formation and its catalytic performance in methanol steam reforming
【24h】

Temperature dependence of Cu-Al spinel formation and its catalytic performance in methanol steam reforming

机译：温度依赖Cu-Al尖晶石的形成及其催化性能在甲醇蒸汽改革

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

A series of Cu-Al spinel nanoparticles have been prepared by a green solid phase reaction method between 800 and 1200 degrees C. Characterization techniques show a strong temperature dependence of the textural and crystal properties, reduction behavior, and surface composition. It is illustrated that the prepared materials rich in Al were mixed spinel solid solutions having a surface Cu/Al ratio lower than the bulk. The samples have surface areas of 19.9-86.6 m(2) g(-1) with spinel crystallite sizes between 8.7 and 34.5 nm. The catalytic behavior of these spinel catalysts together with a reference Cu/gamma-Al2O3 sample is studied in methanol steam reforming (MSR). By omitting the pre-reduction step, the Cu-Al spinel catalysts present an initial increase and then a gradual decrease of conversion rate with time on stream, which leads to enhanced catalytic performances compared to the conventionally adopted pre-reduction method. During the catalytic reaction, the catalyst is firstly activated in situ by non-spinel Cu2+ followed by the gradual release of more active Cu from the spinel structure. The in situ generated Cu species present high catalytic ability and simultaneously agglomerate to larger nanoparticles, which seem to be well stabilized by surface defect spinels rather than by gamma-Al2O3. The sample obtained at 950 degrees C reveals the best catalytic performance, showing the highest activity and durability. In addition, several key points for a good spinel catalyst are proposed.
机译：一系列Cu-Al尖晶石纳米颗粒由一个绿色的固相的反应方法在800年和1200度c .表征技术显示强烈依赖于温度结构和晶体性能的降低行为和表面组成。说明准备的材料丰富艾尔是混合尖晶石有坚实的解决方案铝/铜表面比率低于大部分。样品的表面积19.9 - -86.6 m (2)8.7 g(1)与尖晶石微晶大小之间和34.5纳米。尖晶石催化剂一起参考铜/ gamma-Al2O3样品研究了甲醇蒸汽转化(MSR)。pre-reduction一步,Cu-Al尖晶石催化剂现在一个初始然后逐渐增加转化率随时间的下降流,导致增强的催化性能相比传统的采用pre-reduction方法。反应,催化剂首先激活现场由non-spinel Cu2 +其次是渐进的释放更积极的立方尖晶石结构。同时存在高催化能力更大的纳米颗粒结块,这似乎良好稳定的表面缺陷尖晶石而不是gamma-Al2O3。在950摄氏度显示最好的催化性能,展示活动和最高耐久性。好尖晶石催化剂提出了。

著录项

相似文献

  • 外文文献
  • 中文文献
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