Highly dispersive Au nanoparticles on TiO2 nanofibers as a supported catalyst synthesized from Al-Ti-Au intermetallic compound

[Display omitted] •Highly dispersive Au nanoparticles onto TiO2 nanofibers obtained from Al67Au8Ti25.•Al75−xTi25Aux (x = 8–15) with the thermodynamically stable L12 phase were formed.•Na-TiOx would hinder the atom absorption and thus decrease the catalytic activity.•The heat treatment under CO/O2/He flow is effective to activate for the Au/TiO2. In the present study, we highly dispersed the Gold nanoparticles onto TiO2 nanofibers from leached Al-Ti-Au intermetallic compounds (IMCs) as a catalyst. The IMCs have an ordered structure, which could let the substitutional Au atoms neighboring to Ti atoms in IMC structure. The Al-based IMC single phase was proposed to obtain a high specific area and highly dispersive Au nanoparticles instead of the solid solution after leaching. Therefore, single phase L12-Al67Ti25Au8 was prepared and homogenized by arc-melting and conducted annealing. The ingot of L12-Al67Ti25Au8 was crushed and gathered under 25 µm as precursors. The leaching processes were using the aq. NaOH and aq. HCl. The removal Al of the precursors achieved 95%, and exhibits the special urchin-like particles with TiOx nanofibers. The urchin-like morphology provided a high surface area. After heat treatment, the TiOx transformed to the anatase TiO2 at 500 °C for 2 h under the air or CO/O2/He. The TEM images showed lots of Gold nanoparticles dispersing homogeneously onto the TiOx nanofibers. The CO conversion efficiency of Au/TiO2 was 50% at 50 °C without heat-treatment. Although the contribution mainly attributed to Au nanoparticles, Au/TiO2 exhibited significantly higher catalytic activity than Au/TiOx composite. The CO oxidation activity Au/TiO2 could reach up to 98% when as lower as 50 °C.