...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of soil science and plant nutrition >Iron-bearing minerals from soils developing on volcanic materials from Southern Chile: Application in heterogeneous catalysis
【24h】

Iron-bearing minerals from soils developing on volcanic materials from Southern Chile: Application in heterogeneous catalysis

机译：来自智利南部火山材料上发育的土壤中的含铁矿物：在非均相催化中的应用

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

摘要

Abstract: Chilean soils derived from volcanic ashes are a natural source of iron oxides. Due to their properties, mineralogy, and surface characteristics, iron oxides from Chilean soils are potential candidates for technological applications such as heterogeneous catalysis. However, before a direct application in catalysis, pre-treatment methods are necessary to concentrate iron oxides from bulk volcanic soils. Here, we provide a comprehensive review of pre-treatment strategies for iron oxide concentration including physical separation and selective chemical dissolutive methods for application in catalytic processes, such as the water gas shift (WGS) and Fenton reactions. For preparation of WGS catalyst from volcanic soils, thermal treatment has been demonstrated to be effective, yielding enhanced results for Andisols compared to Ultisols. Based on mineralogical characterisation, it seems that WGS reaction efficiency depends on mineralogical phase shift and the changes of Fe2+/Fe3+ ratio, produced through heating. In addition, Ultisols have shown as efficient catalysts in Fenton and Fenton-like processes, after application of physical and chemical pre-treatments to different size-fractions of the soil sample, improving the yield performance of catalysts. Magnetic separates from the Ultisol sand fraction (compared to the silt+clay fractions) demonstrate the best catalytic performance as Fenton reagent due to their natural magnetite and titanomagnetite content. Application of NaOH selective dissolutive treatment to silt+clay fraction of volcanic soils also produces Fenton and Fenton-like catalyst with improved performance. Our review indicates that catalytic performance can be explained not only by the iron oxide mineral content but also by their characteristics and magnetic properties. The application of the appropriate physical and chemical pre-treatment methods can modulate and enhance the catalytic capabilities of iron oxides from volcanic soils.
机译：摘要：源自火山灰的智利土壤是氧化铁的天然来源。由于它们的特性，矿物学和表面特性，来自智利土壤的氧化铁是诸如多相催化等技术应用的潜在候选者。但是，在直接应用于催化之前，必须采取预处理方法以从散装火山土壤中浓缩氧化铁。在这里，我们对氧化铁浓度的预处理策略进行了全面回顾，包括物理分离和选择性化学溶解方法，这些方法可用于催化工艺，例如水煤气变换（WGS）和Fenton反应。对于从火山土壤中制备WGS催化剂，热处理已被证明是有效的，与Ultisols相比，Andisols的处理效果更高。基于矿物学特征，似乎WGS反应效率取决于矿物相变和通过加热产生的Fe2 + / Fe3 +比值的变化。另外，在对不同大小的土壤样品进行物理和化学预处理后，Ultisols在Fenton和类似Fenton的工艺中显示出有效的催化剂，从而提高了催化剂的产率。与Ultisol砂级分（与淤泥+粘土级分相比）的磁性分离物由于其天然磁铁矿和钛磁铁矿含量而显示出作为Fenton试剂的最佳催化性能。将NaOH选择性溶解处理应用于火山土的粉土+粘土组分也可以生产出性能得到改善的Fenton和类Fenton催化剂。我们的评论表明，催化性能不仅可以由氧化铁矿物质含量来解释，而且可以由它们的特性和磁性来解释。适当的物理和化学预处理方法的应用可以调节和增强来自火山土壤的氧化铁的催化能力。

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