Superior Stability of Au/SiO(2) Compared to Au/TiO(2) Catalysts for the Selective Hydrogenation of Butadiene

[Image: see text] Supported gold nanoparticles are highly selective catalysts for a range of both liquid-phase and gas-phase hydrogenation reactions. However, little is known about their stability during gas-phase catalysis and the influence of the support thereon. We report on the activity, selectivity, and stability of 2–4 nm Au nanoparticulate catalysts, supported on either TiO(2) or SiO(2), for the hydrogenation of 0.3% butadiene in the presence of 30% propene. Direct comparison of the stability of the Au catalysts was possible as they were prepared via the same method but on different supports. At full conversion of butadiene, only 0.1% of the propene was converted for both supported catalysts, demonstrating their high selectivity. The TiO(2)-supported catalysts showed a steady loss of activity, which was recovered by heating in air. We demonstrated that the deactivation was not caused by significant metal particle growth or strong metal–support interaction, but rather, it is related to the deposition of carbonaceous species under reaction conditions. In contrast, all the SiO(2)-supported catalysts were highly stable, with very limited formation of carbonaceous deposits. It shows that SiO(2)-supported catalysts, despite their 2–3 times lower initial activities, clearly outperform TiO(2)-supported catalysts within a day of run time.