THESIS
2018
Abstract
Volatile organic compounds (VOCs) are an important type of indoor air pollutant that
threatens both environment and human health. Catalytic remediation is an attractive method
to treat VOCs, but most catalysts are insufficiently active at low temperatures ( 200 °C) or
in a humid environment. This work combines both experiments and studies of the catalytic
mechanism to identify the candidate catalytic materials. Cerium oxide and titanium dioxide
were employed as support materials. Vanadia and nano-gold/platinum/palladium catalysts
were deposited on these materials to enhance the catalytic performance. Operando
methodology was employed to study the relationship between catalytic performance and
adsorption of VOCs at the active sites. Aerogel technology was introduced to improve th...[
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Volatile organic compounds (VOCs) are an important type of indoor air pollutant that
threatens both environment and human health. Catalytic remediation is an attractive method
to treat VOCs, but most catalysts are insufficiently active at low temperatures (< 200 °C) or
in a humid environment. This work combines both experiments and studies of the catalytic
mechanism to identify the candidate catalytic materials. Cerium oxide and titanium dioxide
were employed as support materials. Vanadia and nano-gold/platinum/palladium catalysts
were deposited on these materials to enhance the catalytic performance. Operando
methodology was employed to study the relationship between catalytic performance and
adsorption of VOCs at the active sites. Aerogel technology was introduced to improve the
catalytic activity in wet condition. Ceria-silica aerogel with a large surface area (ca. 300-500
m
2·g
-1) and well-dispersed ceria clusters demonstrate stable activity in the presence of water
vapor, overcoming the decline in catalytic activity caused by humidity. In addition, the
transition metal oxides derived from metal organic frameworks (MOFs) were investigated
systematically for remediation of VOCs. The light-off temperatures are all less than 200 °C
for metal oxides such as MnO
x, Co
3O
4, CuO, and CeO
2 derived from MnBDC, ZIF-67,
CuBDC, and CeBDC, respectively. The 2D rhombic binary metal oxides CeCuO
x derived by
pyrolysis of bimetallic CeCu-MOF exhibits extremely high activity and selectivity oxidizing
toluene with T
50 and T
90 (temperatures for 50% and 90% conversion) at 150 °C and 185 °C
respectively.
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