The effect of different slurry compositions and solvents upon the properties of ZSM5-washcoated cordierite honeycombs for the SCR of NOx with methane

Deposition of Selective Catalytic Reduction Coating on Wire-Mesh Structure by Atmospheric Plasma Spraying

A series of catalytic coatings consisting of MnOx-CeO2 and TiO2 support were prepared by atmospheric plasma spraying, which was aimed at the application of selective catalytic reduction (SCR) of NOx. The effect of the load of active component on the coating was firstly studied. The results showed that all the coating presented the highest catalytic activity at approximately 350 °C and the coating with the composition of 20MnOx/5CeO2/TiO2 (wt%) achieved the most powerful performance. The coating was then prepared on a wire-mesh structure substrate, which can be easily assembled as a gas filter. The results showed that the specific surface area was greatly increased resulting in the significant improvement of the catalytic activity of the coating. This strategy offered a promising possibility of removing NOx and particulate fliting simultaneously in industrial applications.

Preparation of palygorskite coated cordierite as supports of manganese based catalysts for low-temperature NOx removal from diesel exhausts by NH3 selective catalytic reduction

Cordierite honeycomb ceramic (CC) was immersed in PG–water mixed slurry to prepare a palygorskite (PG) coated CC as a catalyst carrier (PG–CC).

BETA zeolite thin films supported on honeycomb monoliths with tunable properties as hydrocarbon traps under cold-start conditions

A high percentage of hydrocarbon (HC) emissions from gasoline vehicles occur during the cold-start period. Among the alternatives proposed to reduce these HC emissions, the use of zeolites before the three-way catalyst (TWC) is thought to be very effective. Zeolites are the preferred adsorbents for this application; however, to avoid high pressure drops, supported zeolites are needed. In this work, two coating methods (dip-coating and in situ crystallization) are optimized to prepare BETA zeolite thin films supported on honeycomb monoliths with tunable properties. The important effect of the density of the thin film in the final performance as a HC trap is demonstrated. A highly effective HC trap is prepared showing 100% toluene retention, accomplishing the desired performance as a HC trap, desorbing propene at temperatures close to 300 °C, and remaining stable after cycling. The use of this material before the TWC is very promising, and works towards achieving the sustainability and environmental protection goals.