BCC-Cu nanoparticles: from a transient to a stable allotrope by tuning size and reaction conditions.

ABSTRACT: 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 Cu^I precursor, [Cu₄O^tBu₄], 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

SUBMITTER: Alfke JL 

PROVIDER: S-EPMC9554935 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature