Molten salts are promising catalysts. How to apply in practice?

A diesel soot filter with a Cs2SO4.V2O5 molten salt diesel soot oxidation catalyst has been developed. An engine test-bench was used to test it in diesel exhaust gas with ELPI analysis and to deposit diesel soot on filters for temperature programmed oxidation experiments. Molten salt (Cs2SO4.V2O5) based catalytic foam has an onset temperature for catalytic oxidation of 320 degreesC. This is a promising temperature for continuous filter-regeneration applications. Unfortunately the liquid state of the catalyst makes it unfit for the very effective wall-flow monolith filter, and necessitates the use of a foam filter as support. The onset temperature of the catalytic foam of 320 degreesC is still too high to justify a change from wall-flow monolith to foam, as ceramic foam is a less effective filter than the wall-flow monolith. Foams are no "absolute" filters, and should be optimized for each application.