TY - JOUR
T1 - Robust gold-decorated silica-titania pebbles for low-temperature CO catalytic oxidation
AU - Lim, Suo Hon
AU - Phonthammachai, Nopphawan
AU - Zhong, Ziyi
AU - Teo, Jaclyn
AU - White, T. J.
PY - 2009/8/18
Y1 - 2009/8/18
N2 - A deposition-precipitation (DP) process was used to prepare silica-titania core-shell pebbles decorated with nanocrystalline gold suitable for low-temperature catalytic oxidation of carbon monoxide (CO). The microstructure, phase content, crystallography, and catalytic activity were correlated with the pH (3-8), aging time (15,30,60 min), and heat treatment employed for gold crystallization (200-400°C). A homogeneous metal distribution, high gold loading (3.7-4.4 wt %), and superior interfacial adhesion between gold and titania were obtained when the support pebbles were prepared at 600°C, a temperature lower than that required for the anatase-to-rutile transformation. Nucleation and growth of {111} faceted gold was favored at mid-pH (6.4-8), while smaller crystals (<7.5 nm) were obtained at short aging times (≤60 min) and low growth temperatures (≤300°C). Catalytic activity was optimized by homogeneously dispersing gold nanocrystals (3 nm) using pH 6.4 and an aging time of 30 min. These robust materials may offer superior activity and lifetimes when deployed in fluidized bed catalytic cracking units.
AB - A deposition-precipitation (DP) process was used to prepare silica-titania core-shell pebbles decorated with nanocrystalline gold suitable for low-temperature catalytic oxidation of carbon monoxide (CO). The microstructure, phase content, crystallography, and catalytic activity were correlated with the pH (3-8), aging time (15,30,60 min), and heat treatment employed for gold crystallization (200-400°C). A homogeneous metal distribution, high gold loading (3.7-4.4 wt %), and superior interfacial adhesion between gold and titania were obtained when the support pebbles were prepared at 600°C, a temperature lower than that required for the anatase-to-rutile transformation. Nucleation and growth of {111} faceted gold was favored at mid-pH (6.4-8), while smaller crystals (<7.5 nm) were obtained at short aging times (≤60 min) and low growth temperatures (≤300°C). Catalytic activity was optimized by homogeneously dispersing gold nanocrystals (3 nm) using pH 6.4 and an aging time of 30 min. These robust materials may offer superior activity and lifetimes when deployed in fluidized bed catalytic cracking units.
UR - http://www.scopus.com/inward/record.url?scp=68649099750&partnerID=8YFLogxK
U2 - 10.1021/la9007262
DO - 10.1021/la9007262
M3 - 文章
C2 - 19719230
AN - SCOPUS:68649099750
SN - 0743-7463
VL - 25
SP - 9480
EP - 9486
JO - Langmuir
JF - Langmuir
IS - 16
ER -