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High-Entropy-Alloy Nanocrystal Based Macro- and Mesoporous Materials.

Maria Letizia De MarcoWalid BaazizSharmin SharnaFrançois DevredClaude PoleunisAlexandre Chevillot-BiraudSophie NowakRyma HaddadMateusz OdziomekCédric BoissiereDamien P DebeckerOvidiu ErsenJennifer PeronMarco Faustini
Published in: ACS nano (2022)
High-entropy-alloy (HEA) nanoparticles are attractive for several applications in catalysis and energy. Great efforts are currently devoted to establish composition-property relationships to improve catalytic activity or selectivity. Equally importantly, developing practical fabrication methods for shaping HEA-based materials into complex architectures is a key requirement for their utilization in catalysis. However, shaping nano-HEAs into hierarchical structures avoiding demixing or collapse remains a great challenge. Herein, we overcome this issue by introducing a simple soft-chemistry route to fabricate ordered macro- and mesoporous materials based on HEA nanoparticles, with high surface area, thermal stability, and catalytic activity toward CO oxidation. The process is based on spray-drying from an aqueous solution containing five different noble metal precursors and polymer latex beads. Upon annealing, the polymer plays a double role: templating and reducing agent enabling formation of HEA nanoparticle-based porous networks at only 350 °C. The formation mechanism and the stability of the macro- and mesoporous materials were investigated by a set of in situ characterization techniques; notably, in situ transmission electron microscopy unveiled that the porous structure is stable up to 800 °C. Importantly, this process is green, scalable, and versatile and could be potentially extended to other classes of HEA materials.
Keyphrases
  • metal organic framework
  • aqueous solution
  • highly efficient
  • electron microscopy
  • high resolution
  • tissue engineering
  • quality improvement