In situ Aberration Corrected-Transmission Electron Microscopy of Magnesium Oxide Nanocatalysts for Biodiesels
In situ Aberration Corrected-Transmission Electron Microscopy of Magnesium Oxide Nanocatalysts for Biodiesels
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DOI：
10.1007/s10562-009-0085-x
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发表时间：
2009-07
影响因子：
2.8
通讯作者：
P. Gai;J. Montero;A. Lee;K. Wilson;E. Boyes
中科院分区：
文献类型：
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作者：
P. Gai;J. Montero;A. Lee;K. Wilson;E. Boyes
生物燃料是有前途的可再生能源，可以从植物油原料中提取。虽然固体催化剂在植物油甘油三酯酯交换制生物柴油中显示出很大的前景，但在其加工过程中产生的活性位点和操作表面纳米结构的鉴定对于开发高效的非均相催化剂至关重要。系统的，直接观察的动态氧化镁纳米催化剂从氢氧化镁-甲醇前体进行控制煅烧条件下，使用新的原位畸变校正透射电子显微镜在0.1 nm的水平和量化的催化反应性和物理化学研究。表面结构的修改和扩展的原子尺度滑移缺陷的演变牵连共面阴离子空缺在活性位点的甘油三酯转生物柴油。表面缺陷密度（以及因此极化率）和活性之间的线性相关性提供了一种简单的手段来微调用于生物燃料合成的新的节能纳米催化剂。
Biofuels are promising renewable energy sources and can be derived from vegetable oil feedstocks. Although solid catalysts show great promise in plant oil triglyceride transesterification to biodiesel, the identification of active sites and operating surface nanostructures created during their processing is essential for the development of efficient heterogeneous catalysts. Systematic, direct observations of dynamic MgO nanocatalysts from a magnesium hydroxide-methoxide precursor were performed under controlled calcination conditions using novel in situ aberration corrected-transmission electron microscopy at the 0.1 nm level and quantified with catalytic reactivity and physico-chemical studies. Surface structural modifications and the evolution of extended atomic scale glide defects implicate coplanar anion vacancies in active sites in the transesterification of triglycerides to biodiesel. The linear correlation between surface defect density (and therefore polarisability) and activity affords a simple means to fine tune new, energy efficient nanocatalysts for biofuel synthesis.