Understanding the Preferential Oxidation of Carbon Monoxide (PrOx) Using Size-Controlled Au Nanocrystal Catalyst

作者：Beck Arik; Yang An Chih; Leland Amelia R; Riscoe Andrew R; Lopez Francisco A; Goodman Emmett D; Cargnello Matteo^*

来源：AIChE Journal, 2018, 64(8): 3159-3167.

DOI：10.1002/aic.16206

• preferential CO oxidation (PrOx)
• gold
• colloidal nanocrystals
• support
• size effect

Removing CO from hydrogen streams is an important industrial process. The catalytic preferential oxidation of CO (PrOx) is a promising method for CO removal, leaving the hydrogen concentration unchanged. Here, the effect of size and support on the gold-catalyzed PrOx reaction using size-controlled Au nanocrystals (NCs) is investigated. For all supports, Au NC sizes of 2-5 nm show the highest rates, whereas for larger sizes rates drop. Ceria-supported Au shows by far the best performance. By analyzing the dependency of the reaction rate on the NC diameter, the most active centers for CO oxidation on Au/CeO2 are Au+ corner atoms at the interface with the support, resulting in 2.1 nm Au NCs supported on ceria reaching full O-2 conversion and CO selectivity of about 50%. Therefore, it is suggested that increasing the fraction of Au-ceria interface sites would lead to the best performing materials for this reaction.

• 出版日期2018-8