FABRICATION OF ULTRAFINE NANOPOROUS COPPER STABILIZED BY NOBLE METALS WITH LOW SURFACE DIFFUSIVITY

以Ti-Cu-M（M：Ag，Au，Ni，Pd，Pt）非晶合金为前驱体，在HF溶液中脱合金制备了超细纳米多孔铜（NPC）。经M稳定的NPC的孔径小于10 nm，这与NP Au、NP Pt的孔径相似。与由无M的Ti-Cu非晶前驱体制备的NPC相比，孔径减小约1-2个数量级。M吸附原子的引入抑制了Cu吸附原子在脱合金过程中的快速长距离自由扩散。由于M吸附原子的缓慢扩散导致的表面扩散系数的急剧下降表明，在合金/溶液界面处的扩散控制了NPC的形成。超细纳米粒子催化剂的应用有望取代传统的铂纳米粒子催化剂，一方面可以节约成本，另一方面也可以减少稀有铂资源的消耗。

Ultrafine nanoporous copper (NPC) was fabricated from Ti-Cu-M (M:Ag, Au, Ni, Pd, Pt) amorphous precursor alloys by dealloying in HF solutions. NPCs stabilized by M had a pore size less than 10 nm, which is similar with that of NP Au, NP Pt. In comparison to NPCs fabricated from M-free Ti-Cu amorphous precursors, the pore size decreased about 1-2 orders. The introduction of M adatoms resulted in the suppression of the fast long-distance free diffusion of Cu adatoms during dealloying. The drastic decrease in the surface diffusivity caused by the slow diffusion of M adatoms indicated that the diffusion at the interface of alloy/solution controlled the formation of NPCs. The application of the present ultrafine NPCs has a potential to replace the conventional Pt nanoparticle catalysts, which can save the cost and on the other hand, the decrease of the consuming of rare Pt resources will help our society.