Yukun Zhang, Xinyan Wang, Rongsheng Cai, Sung Jin Park, Ang Li
Supported metal nanoparticles are widely used as heterogeneous catalysts, whose catalytic performance is governed not only by metal composition but also by nanoparticle architecture. Herein, a sol-immobilization strategy was employed to achieve the controlled construction of bimetallic Au-Pd nanoparticles supported on TiO2, including nanosized (3.2-5.6 nm) alloyed AuxPdy nanoparticles as well as core-shell architectures (Au@Pd and Pd@Au). NaBH4-assisted reduction of 4-nitrophenol (4-NP) was selected as a model reaction to explore structure-activity relationships of nanoparticle-based catalysts under well-defined conditions. By maintaining comparable particle sizes and metal loadings, a systematic comparison of structural effects was enabled. The results demonstrate that the catalytic performance of Au-Pd nanoparticles is strongly influenced by the spatial distribution of Pd within the nanoparticles, highlighting the critical role of atomic architecture in governing the apparent activity of bimetallic catalysts in a model surface-mediated reductive transformation.