Microstructural Activation of a Topochemical Reduction Reaction.
Zhilin Liang1, Midori Amano Patino1, Mylène Hendrickx2
1Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, U.K.
ACS Organic & Inorganic Au
|March 1, 2023
Summary
Material synthesis conditions critically impact topochemical reduction reactions. Quenched LaSrNiRuO6 samples with smaller crystal domains and higher strain reduce readily, unlike slow-cooled ones, enabling new material preparation.
Area of Science:
- Solid-state chemistry
- Materials science
- Inorganic synthesis
Background:
- Topochemical reduction reactions are crucial for synthesizing various inorganic materials.
- The synthesis conditions of the precursor phase can significantly influence the success and rate of solid-state reactions.
- LaSrNiRuO6 is an oxidized phase that can be reduced to LaSrNiRuO4.
Purpose of the Study:
- To investigate the effect of synthesis conditions on the topochemical reduction of LaSrNiRuO6 to LaSrNiRuO4.
- To understand the microstructural factors governing the reactivity of the oxidized phase.
- To explore the potential of microstructure control for activating solid-state reactions.
Main Methods:
- Synthesis of LaSrNiRuO6 samples under different conditions (high-temperature quench vs. slow cooling).
- Characterization of the microstructural properties (crystalline domain size, lattice strain) of the synthesized samples.
- Monitoring the progress and completeness of the topochemical reduction reaction.
Main Results:
- Quenched LaSrNiRuO6 samples, featuring smaller crystalline domains and increased lattice strain, were readily converted to LaSrNiRuO4.
- Slow-cooled LaSrNiRuO6 samples exhibited larger domains and lower strain, resulting in incomplete reduction.
- A proposed mechanism suggests that smaller domains enhance reaction kinetics through increased 'plasticity' and lattice strain destabilizes the host phase.
Conclusions:
- Microstructure, specifically crystalline domain size and lattice strain, plays a critical role in the reactivity of materials during topochemical reduction.
- Controlling synthesis conditions to tailor microstructure can 'activate' solid-state reactions.
- This approach expands the range of materials preparable via topochemical reactions.
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