Gold Catalyzes Esterifications

Supported gold and gold-palladium nanoparticles can serve as active catalysts for esterification of diols, according to a study published in Catalysis Science & Technology (DOI: 10.1039/c1cy00254f). The work broadens the list of catalytic transformations mediated by gold, an element that until recently was considered relatively inert. In addition, the study catalogs the effects on catalytic performance of various factors, including catalyst preparation method, support material, and Au/Pd ratio. Gemma L. Brett and Graham J. Hutchings of Cardiff University, in Wales, and coworkers compared commercial and reference gold catalysts supported on titania and iron oxide to ones supported on carbon, silica, and ceria. In tests measuring conversion of 1,2-propanediol to methyl lactate and methyl pyruvate, the team found that its colloidal gold/titania catalyst was comparable in activity but some 10% more selective for methyl lactate compared with a gold/titania reference catalyst. Gold/ceria catalysts were some 45% more selective than the reference but less active. Adding palladium to gold boosted conversion of the diol by up to a factor of four and led to increasing selectivity toward methyl lactate with increasing palladium content, the team reports.