Easy Access to Metallic Copper Nanoparticles with High Activity and Stability for CO Oxidation

Author(s)

Goncalves, Renato V. ^[1] ; Wojcieszak, Robert ^{[2, 3]} ; Wender, Heberton ^[4] ; Dias, Carlos Sato B. ^[5] ; Vono, Lucas L. R. ^[1] ; Eberhardt, Dario ^[6] ; Teixeira, Sergio R. ^[7] ; Rossi, Liane M. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, BR-05508000 Sao Paulo - Brazil

^[2] Univ Lille Nord France, F-59000 Lille - France

^[3] UMR CNRS 8181, UCCS, F-59655 Villeneuve Dascq - France

^[4] Univ Fed Mato Grosso do Sul, Inst Fis, BR-79070900 Campo Grande, MS - Brazil

^[5] LNLS, BR-13083970 Sao Paulo - Brazil

^[6] Univ Caxias Sul, BR-95700000 Bento Goncalves, RS - Brazil

^[7] Univ Fed Rio Grande do Sul, Inst Fis, BR-90046900 Porto Alegre, RS - Brazil

• Document type: Journal article
• Source: ACS APPLIED MATERIALS & INTERFACES; v. 7, n. 15, p. 7987-7994, APR 22 2015.
• Web of Science Citations: 26

Abstract

Copper catalysts are very promising, affordable alternatives for noble metals in CO oxidation; however, the nature of the active species remains unclear and differs throughout previous reports. Here, we report the preparation of 8 nm copper nanoparticles (Cu NPs), with high metallic content, directly deposited onto the surface of silica nanopowders by magnetron sputtering deposition. The as-prepared Cu/SiO2 contains 85% Cu-0 and 15% Cu2+ and was enriched in the Cu phase by H-2 soft pretreatment (96% Cu-0 and 4% Cu2+) or further oxidized after treatment with O-2 (33% Cu-0 and 67% Cu2+). These catalysts were studied in the catalytic oxidation of CO under dry and humid conditions. Higher activity was observed for the sample previously reduced with H-2, suggesting that the presence of Cu-metal species enhances CO oxidation performance. Inversely, a poorer performance was observed for the sample previously oxidized with O-2. The presence of water vapor caused only a small increase in the temperature require for the reaction to reach 100% conversion. Under dry conditions, the Cu NP catalyst was able to maintain full conversion for up to 45 h at 350 degrees C, but it deactivated with time on stream in the presence of water vapor. (AU)

• FAPESP's process: 14/15159-8 - Metal nanoparticles: challenges on the preparation, stabilization and activation for catalysis
• Grantee: Liane Marcia Rossi
• Support type: Regular Research Grants
• FAPESP's process: 11/17402-9 - Development of multifunctional magnetic nanoparticles for cancer therapy
• Grantee: Heberton Wender Luiz dos Santos
• Support type: Regular Research Grants
• FAPESP's process: 13/21323-2 - Development of advanced nickel and copper nanocatalysts highly efficient in syngas production by the reverse water gas shift reaction (RWGS)
• Grantee: Renato Vitalino Gonçalves
• Support type: Scholarships in Brazil - Post-Doctorate