Microstructural Activation of a Topochemical Reduction Reaction.
Microstructural Activation of a Topochemical Reduction Reaction.
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DOI：
10.1021/acsorginorgau.1c00030
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发表时间：
2022-02-02
期刊：
影响因子：
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通讯作者：
Hayward, Michael A
中科院分区：
文献类型：
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作者：
Liang, Zhilin;Amano Patino, Midori;Hendrickx, Mylene;Hadermann, Joke;Hayward, Michael A
将 LaSrNiRuO6 转化为 LaSrNiRuO4 的拓扑化学还原反应的进展取决于用于制备氧化相的合成条件。经过高温淬火的LaSrNiRuO6样品可以容易且快速地转化为LaSrNiRuO4。相反，经过缓慢冷却的样品无法完全还原。这种反应性差异归因于淬火和缓慢冷却样品的不同微观结构，前者比后者具有更小的平均晶域尺寸和更大的晶格应变。提出了解释这种效应的机制，其中小晶域更大的“可塑性”有助于降低还原反应的活化能。此外，我们提出淬火样品中增强的晶格应变也会破坏主体相的稳定性，从而进一步增强反应性。这些观察结果表明，材料的微观结构可用于“激活”固态拓扑化学反应，扩大了此类反应可制备的相的范围。
The progress of the topochemical reduction reaction that converts LaSrNiRuO6 into LaSrNiRuO4 depends on the synthesis conditions used to prepare the oxidized phase. Samples of LaSrNiRuO6 that have been quenched from high temperature can be readily and rapidly converted into LaSrNiRuO4. In contrast, samples that have been slow-cooled cannot be completely reduced. This reactivity difference is attributed to the differing microstructures of the quenched and slow-cooled samples, with the former having much smaller average crystalline domain sizes and larger lattice strains than the latter. A mechanism to explain this effect is presented, in which the greater “plasticity” of small crystalline domains helps lower the activation energy of the reduction reaction. In addition, we propose that the enhanced lattice strain in quenched samples also acts to destabilize the host phase, further enhancing reactivity. These observations suggest that the microstructure of a material can be used to “activate” topochemical reactions in the solid state, expanding the scope of phases that can be prepared by this type of reaction.