Liang Zhilin, Amano Patino Midori, Hendrickx Mylène, Hadermann Joke, Hayward Michael A
Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K.
EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
ACS Org Inorg Au. 2021 Nov 15;2(1):75-82. doi: 10.1021/acsorginorgau.1c00030. eCollection 2022 Feb 2.
The progress of the topochemical reduction reaction that converts LaSrNiRuO into LaSrNiRuO depends on the synthesis conditions used to prepare the oxidized phase. Samples of LaSrNiRuO that have been quenched from high temperature can be readily and rapidly converted into LaSrNiRuO. 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.
将LaSrNiRuO转化为LaSrNiRuO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。从高温淬火的LaSrNiRuO样品可以很容易且快速地转化为LaSrNiRuO。相比之下，缓慢冷却的样品不能完全还原。这种反应性差异归因于淬火和缓慢冷却样品的微观结构不同，前者的平均晶畴尺寸比后者小得多，晶格应变也比后者大。提出了一种解释这种效应的机制，其中小晶畴更大的“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起到使主体相不稳定的作用，进一步提高反应性。这些观察结果表明，材料的微观结构可用于“激活”固态中的拓扑化学反应，扩大了通过此类反应可制备的相的范围。
