Stabilization of reduced copper on ceria aerogels for CO oxidation. Issue 10 (11th September 2020)

• Record Type: Journal Article
• Authors: Pitman, Catherine L.; Pennington, Ashley M.; Brintlinger, Todd H.; Barlow, Daniel E.; Esparraguera, Liam F.; Stroud, Rhonda M.; Pietron, Jeremy J.; DeSario, Paul A.; Rolison, Debra R.
• Is Part Of: Nanoscale advances. Volume 2:Issue 10(2020)
• Page Start: 4547
• Page End: 4556
• Publication Date: 2020-09-11
• Subjects: 620.5
• DOI: 10.1039/d0na00594k
• Languages: English
• ISSNs: 2516-0230

Abstract

Abstract : Copper photodeposited on ceria aerogel yields reduced Cu that binds CO; CO conversion is high when combined with O2 -activating CeO2 . Abstract : Photodeposition of Cu nanoparticles on ceria (CeO2 ) aerogels generates a high surface area composite material with sufficient metallic Cu to exhibit an air-stable surface plasmon resonance. We show that balancing the surface area of the aerogel support with the Cu weight loading is a critical factor in retaining stable Cu 0 . At higher Cu weight loadings or with a lower support surface area, Cu aggregation is observed by scanning and transmission electron microscopy. Analysis of Cu/CeO2 using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy finds a mixture of Cu 2+, Cu +, and Cu 0, with Cu + at the surface. At 5 wt% Cu, Cu/CeO2 aerogels exhibit high activity for heterogeneous CO oxidation catalysis at low temperatures (94% conversion of CO at 150 °C), substantially out-performing Cu/TiO2 aerogel catalysts featuring the same weight loading of Cu on TiO2 (20% conversion of CO at 150 °C). The present study demonstrates an extension of our previous concept of stabilizing catalytic Cu nanoparticles in low oxidation states on reducing, high surface area aerogel supports. Changing the reducing power of the support modulates the catalytic activity of mixed-valent Cu nanoparticles and metal oxide support.