Palladium-gold nanoparticles clean TCE a billion times faster than iron filings - In the first side-by-side tests of a half-dozen palladium- and iron-based catalysts for cleaning up the carcinogen TCE, Rice University scientists have found that palladium destroys TCE far faster than iron -- up to a billion times faster in some cases. The results will appear in a new study in the August issue of the journal Applied Catalysis B: Environmental.