“…Numerous studies have searched for better catalysts, examining particle-size effects 12,15 , metal-oxide-support effects 16,17 , mixed metal oxides 15,18 and ordered mesoporous materials 19 . Bimetallic catalysts 20 , the inclusion of polyoxometallates in liquid-phase media 21 , Au-ceria nanocomposites 22 and embedded Au@CeO 2 catalysts 23 have also been examined, with limited success.…”