College of Chemistry and Materials Science, The Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecular-Based Materials, Anhui Normal University, Wuhu, Anhui Province 241000, China.
Nanoscale. 2016 Aug 11;8(32):14971-8. doi: 10.1039/c6nr02643e.
PtAg alloyed nanostructural catalysts were firstly prepared by co-reduction of AgNO3 and H2PtCl6 precursors in growth solution using a seed-mediated method. By simply changing the molar ratio of the metal precursors, the morphologies of the porous alloyed nanocrystals can be tuned from multipetals to multioctahedra. Simultaneously, the alloy composition can be varied from Pt76Ag24 to Pt66Ag34. The catalytic properties of the prepared PtAg alloyed nanocrystals with a tunable structure and composition were tentatively examined by choosing the reduction of 4-nitrophenol with NaBH4. The reaction rate normalized to the concentration of catalysts was calculated to be 318.9 s(-1) mol(-1) L and 277.4 s(-1) mol(-1) L for Pt70Ag30 and Pt66Ag34 porous catalysts, which is much higher than the pure Pt catalysts. Moreover, PtAg nanostructures can also serve as efficient electrocatalysts toward the methanol oxidation reaction, especially for Pt70Ag30 and Pt66Ag34 porous nanocrystals. The electrocatalytic activity and the durability were both highly enhanced compared to the commercial Pt/C catalyst. In addition, we also investigated the enhancement mechanism.
首先通过在生长溶液中使用种子介导法共还原 AgNO3 和 H2PtCl6 前体来制备 PtAg 合金纳米结构催化剂。通过简单改变金属前体的摩尔比，可以从多花瓣状调控制备出多孔合金纳米晶体的形态为多八面体。同时，合金组成可以从 Pt76Ag24 调变至 Pt66Ag34。通过选择 4-硝基苯酚与 NaBH4 的还原反应，初步考察了具有可调结构和组成的 PtAg 合金纳米晶体的催化性能。将反应速率归一化到催化剂的浓度，Pt70Ag30 和 Pt66Ag34 多孔催化剂的反应速率分别为 318.9 s(-1) mol(-1) L 和 277.4 s(-1) mol(-1) L，远高于纯 Pt 催化剂。此外，PtAg 纳米结构还可以作为甲醇氧化反应的高效电催化剂，尤其是对于 Pt70Ag30 和 Pt66Ag34 多孔纳米晶体。与商业 Pt/C 催化剂相比，电催化活性和耐久性都得到了极大提高。此外，我们还研究了增强机制。
