Fine Tuning of the Structure of Pt–Cu Alloy Nanocrystals by Glycine‐Mediated Sequential Reduction Kinetics

Tailored design of noble metal nanocrystals (NCs) has received considerable interests due to their intrinsic properties and wide range of practical and potential applications in various fi elds, especially in catalysis. [ 1–5 ] Considering the high cost of noble metal catalysts, the substitution of noble metals with inexpensive metals (Cu, Fe, Co, Ni, etc.) has been extensively studied. [ 6–10 ] Meanwhile, it has been reported that the catalytic properties of bimetallic nanostructures are superior to those of their pure counterparts. [ 11–13 ] At present, to make economical and effective alternative catalysts, various synthetic strategies of bimetallic nanoparticles with controlled architectures are being developed. [ 14–16 ] Compared with the synthetic chemistry of single component metal nanocrystals, the coexistence of bimetallic precursors will complicate the reduction kinetics and thus make it more diffi cult to rationally design the growth process of nanocrystals with specifi c structures, especially those with complex structures like hollow and dendrite shapes. It is well known that the reduction sequences of metal precursors are determined by their standard reduction potentials, and usually the ones with high standard reduction potentials could be fi rst reduced. [ 17–19 ] However, the reduction sequence of metal precursors could also be varied by tuning the reduction kinetics by adding appropriate complexation reagents. For example, the standard reduction potentials for Pd 2+ /Pd (0.915 V) and Cu 2+ /Cu (0.342 V) are typically more negative than Pt 2+ /Pt (1.18 V) pairs when they are in the same coordination environment. Zheng and coworkers [ 20 ] reported that the addition of iodide ions to the [Pd(acac) 2 ]/[Pt(acac) 2 ] mixture in the DMF solution results in [PdI 4 ] 2− as the dominating precursors, and thus makes Pd 2+