Pd-Au/TiO₂ bimetallic catalysts with varied Au contents were prepared by the sequential photocatalytic deposition method and the liquid phase catalytic hydrogenation reduction of bromate over these catalysts was investigated. The catalysts were characterized using X-ray diffraction, transmission electron microscope, UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, H₂ chemisorption and energy dispersive spectroscopy. Characterization results showed that Pd atoms were site-deposited on the surface of varied size Au cores and formed Pd-on-Au core-shell like bimetallic nanoparticles on TiO₂. The bimetallic catalysts showed higher Pd dispersions and more exposed active sites than that of Pd/TiO₂, and the amount of exposed active sites first increased then decreased with Au content. For a similar Pd loading, the bimetallic catalyst exhibited volcano-shape activity as a function of Au loading and the highest activity was identified on Pd-Au(1.0)/TiO₂ with Au core size around 8.4 nm. In addition, the catalytic reduction of bromate could be well-fitted by the Langmuir-Hinshelwood model, reflecting an adsorption controlled mechanism.

采用连续光催化沉积法制备了具有不同Au含量的Pd-Au / TiO ₂双金属催化剂，并研究了在这些催化剂上溴酸盐的液相催化加氢还原反应。使用X射线衍射，透射电子显微镜，UV-vis漫反射光谱，X射线光电子光谱，H ₂化学吸附和能量色散光谱对催化剂进行了表征。表征结果表明，Pd原子定点沉积在大小不同的Au核表面上，并在TiO ₂上像双金属纳米粒子一样形成了Au上的Pd-on-Au核-壳。与Pd / TiO ₂相比，双金属催化剂显示出更高的Pd分散度和更多的暴露活性位点，并且暴露的活性位点的数量先随Au含量的增加而减少。对于类似的Pd负载，双金属催化剂表现出火山形状的活性，作为Au负载的函数，并且在Au核心尺寸约为8.4 nm的Pd-Au（1.0）/ TiO ₂上确定了最高的活性。此外，Langmuir-Hinshelwood模型可以很好地拟合溴酸盐的催化还原反应，这反映了吸附控制的机理。