TY - JOUR
T1 - Development of etched SiO2@Pt@ZrO2 core-shell catalyst for CO and C3H6 oxidation at low temperature
AU - Lee, Eun Jun
AU - Seo, Yaeun
AU - Park, Haney
AU - Kim, Min June
AU - Yoon, Dalyoung
AU - Choung, Jin Woo
AU - Kim, Chang Hwan
AU - Choi, Jungkyu
AU - Lee, Kwan Young
N1 - Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2016R1A5A1009592).
Publisher Copyright:
© 2021
PY - 2022/2/1
Y1 - 2022/2/1
N2 - In our previous study, we conducted CO oxidation with SiO2@Pd@CeO2 catalysts. However, the limit of the CeO2 shell thickness limited the thermal stability. So, in this study, thick ZrO2 shell was introduced to improve thermal stability. SiO2@Pt@ZrO2 catalysts were examined for the simultaneous oxidation of CO and hydrocarbons. SiO2@Pt@ZrO2 catalysts had improved thermal stability compared to Pt/SiO2 or Pt/ZrO2 after aging at 750 °C for 25 h. However, fresh SiO2@Pt@ZrO2 catalysts showed low oxidation activity because of the low gas accessibility due to the thick ZrO2 shell. Therefore, we proposed etched SiO2@Pt@ZrO2 catalysts for enhanced gas accessibility. The selective etching of SiO2 was adjusted by varying the KOH concentration. TEM images confirmed that the void space of the core-shell catalysts increased as the concentration of KOH increased. The exposed Pt surface area increased as the void space of the core-shell catalysts was increased. On the other hand, in excessively etched 3.2 M catalysts, the core-shell structure collapsed. Etched catalysts which maintain the core-shell structure improve thermal stability after hydrothermal aging. As a result, 1.6 M catalysts showed the best simultaneous oxidation of CO and hydrocarbons, and we confirmed that properly etched catalysts enhanced the oxidation activity and thermal stability.
AB - In our previous study, we conducted CO oxidation with SiO2@Pd@CeO2 catalysts. However, the limit of the CeO2 shell thickness limited the thermal stability. So, in this study, thick ZrO2 shell was introduced to improve thermal stability. SiO2@Pt@ZrO2 catalysts were examined for the simultaneous oxidation of CO and hydrocarbons. SiO2@Pt@ZrO2 catalysts had improved thermal stability compared to Pt/SiO2 or Pt/ZrO2 after aging at 750 °C for 25 h. However, fresh SiO2@Pt@ZrO2 catalysts showed low oxidation activity because of the low gas accessibility due to the thick ZrO2 shell. Therefore, we proposed etched SiO2@Pt@ZrO2 catalysts for enhanced gas accessibility. The selective etching of SiO2 was adjusted by varying the KOH concentration. TEM images confirmed that the void space of the core-shell catalysts increased as the concentration of KOH increased. The exposed Pt surface area increased as the void space of the core-shell catalysts was increased. On the other hand, in excessively etched 3.2 M catalysts, the core-shell structure collapsed. Etched catalysts which maintain the core-shell structure improve thermal stability after hydrothermal aging. As a result, 1.6 M catalysts showed the best simultaneous oxidation of CO and hydrocarbons, and we confirmed that properly etched catalysts enhanced the oxidation activity and thermal stability.
KW - Etched SiO@Pt@ZrO
KW - Simultaneous CO and hydrocarbon oxidation
KW - Thermal stability
UR - http://www.scopus.com/inward/record.url?scp=85118473499&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2021.151582
DO - 10.1016/j.apsusc.2021.151582
M3 - Article
AN - SCOPUS:85118473499
SN - 0169-4332
VL - 575
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 151582
ER -