Fabrication of a Novel Catalyst Reactor with Improved Strength and Catalytic Performance Used for Automotive Exhaust Treatment

Abstract

Yttria-stabilized zirconia hollow fibers (YSZ-HFs) containing radial wall microchannels with one end opening on the inner surface were prepared, and robust reactor modules of YSZ-HFs for automotive emission were prepared by bundling fibers with cement glue. 100% open-cell ratio and the unique microstructure of the YSZ-HFs catalytic reactor facilitated deposition of LaMnO3 three-way catalysts. Compared with the commonly used cordierite (2MgO-2Al2O3-5SiO2) honeycombs (CHs), the YSZ-HFs improved the reducibility and sintering resistance of the attached catalyst film. Higher effective conversion of CO and NO was found in the YSZ-HFs samples in comparison to the CHs samples. Moreover, the YSZ-HFs samples achieving higher flexural strength (~135 MPa) can better preserve the mechanical properties and the integrity of the catalyst film after 200 thermal shock cycles at 900 °C, due to the small thermal mismatch between the YSZ-HFs and the catalysts, as well as the intrinsic merit of zirconia.

Prevention in Thermal Crack Formation in Chabazite (CHA) Zeolite Membrane by Developing Thin Top Zeolite and Thick Intermediate Layers

“…In addition to the intermediate layer, the selection of the support materials was important. However, the use of high CTE support such as stainless steel support (10.1–17.3 × 10 −6 K −1 ) and YSZ (10.5 × 10 −6 K −1 ) was not effective in preventing thermal defects even though the intermediate layer was well developed [ 13 , 16 , 18 , 24 , 31 , 33 , 42 ]. In their SEM images, an interfacial gap was observed between the zeolite layer and the support and most membranes showed thousands of separation factors.…”