Catalyst adhesion enhancement by porous TiO2 layer formed on anodized titanium honeycomb substrate.

Titanium honeycomb substrates having TiO 2 surface with nano- to micro-sized pores were prepared by electrochemical anodization and used to make Pt-based oxidation catalyst monoliths without conventional oxide-based washcoat layers for pre-turbocharger catalyst (PTC) applications exposed to harsh conditions under very high flow rates of exhaust gas and engine vibration. Adhesion strength and CO/C 3 H 6 oxidation performance of the catalysts were compared with conventional washcoated FeCrAl monolith catalysts. The intermediate porous TiO 2 layer formation by the anodization can dramatically enhance the catalyst adhesion strength without sacrificing the catalytic performance under GHSV (gas hourly space velocity) higher than 100,000 h−1 for PTC. [ABSTRACT FROM AUTHOR]