(130b) Atomically Dispersed Au-(OH)x Species On Titania Catalyze the Low-Temperature Water-Gas Shift Reaction

The WGS reaction is important in upgrading H₂-rich fuel gas streams. For application of the latter to fuel cell systems, a new generation of catalysts is being developed to withstand the particularly stringent operating conditions involved. Atomically dispersed gold species on titania were prepared by a novel approach combining gold deposition followed by UV irradiation with or without subsequent cyanide leaching. The new materials catalyze the low-temperature water-gas shift (WGS) reaction and are stable. The active site comprises Au(OH)_x clusters, which are stably anchored on the titania sites in long-term reaction conditions. H₂O dissociation is facile on these sites. The present work also provides the fundamental evidence to support that atomically dispersed gold species associated with adjacent surface oxygen as –OH groups are the active sites for the WGS reaction.  These serve as the active centers for the WGS reaction, regardless of the support oxide types (TiO₂, CeO₂, La₂O₃, or Fe₂O₃ etc.). Gold nanoparticles are spectator species on any of these supports.