TY - JOUR
T1 - Ultrasound-assisted nanocasting fabrication and excellent catalytic performance of three-dimensionally ordered mesoporous chromia for the combustion of formaldehyde, acetone, and methanol
AU - Xia, Yunsheng
AU - Dai, Hongxing
AU - Zhang, Lei
AU - Deng, Jiguang
AU - He, Hong
AU - Au, Chak Tong
N1 - Funding Information:
The work described above was supported by the NSF of China (grant No. 20973017 ), the Creative Research Foundation of Beijing University of Technology ( 00500054R4003 ), the “863” Key Program of Ministry of Science and Technology of China ( 2009AA063201 ), the PHR200907105 of the Beijing Municipal Commission of Education , and the NSF of Beijing Municipality (Key Class B project of grant No. KZ200610005004 ).
PY - 2010/10/11
Y1 - 2010/10/11
N2 - Rhombohedral chromia with three-dimensionally (3D) ordered mesopore structures were fabricated adopting the ultrasound-assisted nanocasting strategy with 3D ordered mesoporous silica (KIT-6) as hard template and chromium nitrate as metal source. The physicochemical properties of the materials were characterized by the XRD, TGA/DSC, BET, TEM/SAED, XPS, and H2-TPR techniques, and their catalytic activities were evaluated for the oxidation of typical volatile organic compounds (VOCs), such as formaldehyde, acetone, and methanol. It is found that there were tri-, penta-, and hexavalent chromium ions in the 3D mesoporous structure. Compared to the bulk chromia, the mesoporous chromia materials were larger in surface area (69-124m2/g) and could be reduced at lower temperatures. Among the chromia catalysts, the meso-Cr-400 one obtained after calcination at 400°C showed the best performance. Over meso-Cr-400 at space velocity=30,000mL/(gh), formaldehyde, acetone, and methanol conversions achieved 90% at 117, 124, and 130°C, respectively; the corresponding apparent activation energies were 45.6, 49.7, and 50.8kJ/mol. It is concluded that the ultrasound treatment was a key step to improve the mesoporosity quality of the chromia materials during the nanocasting process, and the factors, such as low-temperature reducibility, 3D ordered mesoporous architecture, and high-surface area, were responsible for the excellent catalytic performance of meso-Cr-400.
AB - Rhombohedral chromia with three-dimensionally (3D) ordered mesopore structures were fabricated adopting the ultrasound-assisted nanocasting strategy with 3D ordered mesoporous silica (KIT-6) as hard template and chromium nitrate as metal source. The physicochemical properties of the materials were characterized by the XRD, TGA/DSC, BET, TEM/SAED, XPS, and H2-TPR techniques, and their catalytic activities were evaluated for the oxidation of typical volatile organic compounds (VOCs), such as formaldehyde, acetone, and methanol. It is found that there were tri-, penta-, and hexavalent chromium ions in the 3D mesoporous structure. Compared to the bulk chromia, the mesoporous chromia materials were larger in surface area (69-124m2/g) and could be reduced at lower temperatures. Among the chromia catalysts, the meso-Cr-400 one obtained after calcination at 400°C showed the best performance. Over meso-Cr-400 at space velocity=30,000mL/(gh), formaldehyde, acetone, and methanol conversions achieved 90% at 117, 124, and 130°C, respectively; the corresponding apparent activation energies were 45.6, 49.7, and 50.8kJ/mol. It is concluded that the ultrasound treatment was a key step to improve the mesoporosity quality of the chromia materials during the nanocasting process, and the factors, such as low-temperature reducibility, 3D ordered mesoporous architecture, and high-surface area, were responsible for the excellent catalytic performance of meso-Cr-400.
KW - KIT-6-templating strategy
KW - Mesoporous chromia catalyst
KW - Ultrasound-assisted nanocasting method
KW - Volatile organic compound combustion
UR - http://www.scopus.com/inward/record.url?scp=77957226006&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2010.07.037
DO - 10.1016/j.apcatb.2010.07.037
M3 - Journal article
AN - SCOPUS:77957226006
SN - 0926-3373
VL - 100
SP - 229
EP - 237
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
IS - 1-2
ER -