Effect of hollow silica support on the reduction performance of harmful gases of 3Pt–2MgO–3ZrO2–2CeO2 for DOC

• One side of the hollow polymer support was open and the other side was closed.
• The hollow silica-based DOC showed inferior catalyst performance compared to that the γ-Al2O3 support-based DOC.
• The performance of hollow silica-based DOC due to frequent calcination was degraded.

The aim of the present study is to investigate the reduction of harmful gases using the diesel oxidation catalyst on hollow silica support with a large surface area. One side of the hollow polymer support was open and the other side was closed, so exhaust gas molecules can collide and stay on the back-side of the polymer membrane to prolong the reaction time. In the case of fresh 3Pt–2MgO–3ZrO2–2MgO/hollow silica, the LOT 50 value of CO was about 175 °C, while that of fresh catalyst supported by Al2O3 support was 150 °C. The hollow silica-based diesel oxidation catalyst (DOC) showed inferior catalyst performance compared to that of the γ-Al2O3 support-based DOC. There was a reduction in the number of active sites because of the weak structure of hollow silica. In addition, the agglomeration of Pt particles by repeated calcinations and hydrothermal aging further reduced the catalyst performance. The catalyst performance can be improved by increasing the frequency of gas molecule collisions using the shape characteristics of hollow silica supports with a lager specific surface area.

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