The Active Site in Nanoparticle Gold Catalysis

摘要

Most pollution from U.S. automobiles is emitted in the first 5 min after startup. This is because Pt- or Pd-based catalysts currently used in automobile exhaust cleanup are inactive below about 200°C. Gold-based catalysts present a potential solutionto this cold-startup problem. Gold nanoparticles dispersed across the surfaces of certain oxides have been shown to be amazingly active and selective as catalysts for a variety of important reactions. There is intense interest in these catalysts for carton monoxide oxidation, because they are active at room temperature. Interestingly, the low-temperature gold catalysts are totally inactive unless the gold is in the form of particles smaller than ～8 nm in diameter (7-3). Though gold nanoparticles havebeen perhaps the most widely studied catalyst system in the last 2 to 3 years, the structure of the active site has remained elusive. On page 252 in this issue, Chen and Goodman (4) take an important step toward characterizing the active site.