Alfke, J. L., Müller, A., Clark, A. H., Cervellino, A., Plodinec, M., Comas-Vives, A., Copéret, C., & Safonova, O. V. (2022). BCC-Cu nanoparticles: from a transient to a stable allotrope by tuning size and reaction conditions. Physical Chemistry Chemical Physics, 24(39), 24429–24438. https://doi.org/10.1039/D2CP03593F
Metallic copper generally adopts an FCC structure. In this work, we detect highly unusual BCC-structured Cu nanoparticles as a transient intermediate during the H₂ reduction of a Cuᴵ precursor, [Cu₄OᵗBu₄], grafted onto the surface of partially dehydroxylated silica. The Cu BCC structure, assigned by in situ Cu K-edge XANES and EXAFS, as well as in situ synchrotron PXRD, converts upon heating into the most commonly found FCC allotrope. DFT calculations show that the BCC-Cu phase is in fact predicted to be more stable for small particles, and that their stability increases at lower H₂ concentrations. Using this knowledge, we show that it is possible to synthesize BCC-structured Cu nanoparticles as a stable allotrope by reduction of the same grafted precursor either in 10% H₂ diluted in Ar or 100% H₂ at low temperature.
en
Project (external):
Swiss National Foundation Spanish MEC and European Social Fund Spanish “Ministerio de Ciencia, Innovación y Universidades”
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Project ID:
CRSII5_183495 RyC-2016-19930 PGC2018-100818A-I00
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Research Areas:
Materials Characterization: 30% Surfaces and Interfaces: 30% Modeling and Simulation: 40%
CC BY-NC 3.0
