Journal
NANOSCALE
Volume 9, Issue 39, Pages 15033-15043Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/c7nr06018a
Keywords
-
Categories
Funding
- China Postdoctoral Science Foundation [2016M600221]
- National Natural Science Foundation of China [91645117, 21606243, 21473223, 91545119, 21773269]
- Youth Innovation Promotion Association CAS [2015152]
Ask authors/readers for more resources
Although nanosized Au clusters have been well developed for many applications, fundamental understanding of their adsorption/activation behaviors in catalytic applications is still lacking, especially when other elements provide promotion or hybridization functions. Au hybridized with Cu element is a highly investigated system; Cu is in the same element group as Au and thus displays similar physicochemical properties. However, their hybrids are not well understood in terms of their chemical states and adsorption/ activation properties. In this work, typical gamma-Al2O3-supported Au and CuO as well as Au-CuO nanoparticles were prepared and characterized to explore their adsorption/activation properties in depth using CO as a probe molecule using advanced techniques, such as XPS, HR-TEM, temperature programmed experiments and operando DRIFT combined with mass spectra. It was found that gold and copper can both act as active sites during CO adsorption and activation. The CO-TPD and operando DRIFT results also revealed that CO molecules were able to react with surface oxygenated species, resulting in the direct formation of CO2 over the three samples in the absence of gaseous O-2. The gold step sites (Austep) participated more readily in the reaction, especially under gaseous O-2-free conditions. During adsorption, CO molecules were more preferentially adsorbed on Au-0 sites at lower temperature comparing with those on the Cu-0 sites. However, competitive adsorption occurred between CO adsorbed on Au-0 and Cu-0 with increased reaction temperature, and the synergy between the Au and Cu compositions was too strong to suppress the adsorption and activation of the CO molecules. The dynamic adsorption equilibrium over 120 degrees C to 200 degrees C resulted in the appearance of a hysteresis performance platform.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available