State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China.
Nanoscale. 2018 Jun 21;10(24):11357-11364. doi: 10.1039/c8nr02527d.
Nanoscale PtPb catalysts with core-shell structure have been actively explored in recent years owing to their outstanding catalytic activity. We report on a new class of PtPb nanoplate (NP) catalyst with a novel structure realized by ion irradiation modification, which contains an interface formed by a crystalline phase and an amorphous phase simultaneously in an annular state. Significantly, the PtPb NP with the new structure shows superior catalytic activity towards the methanol oxidation reaction (MOR). The specific activity of PtPb NPs with the new structure reaches 4.32 mA cm-2 towards the MOR and the mass activity reaches 1.31 A mg-1, which is 1.9-fold and 1.4-fold greater than those for the original crystalline PtPb NPs, respectively. The outstanding catalytic activity could be attributed to the presence of the interface between a crystalline phase and an amorphous phase with a special electronic structure created by ion irradiation. Density functional theory calculations reveal that the novel interface activates the C-H and O-H bonds, leading to high electrocatalytic activity, and optimizes the adsorption of hydroxyl and intermediates on the surface to facilitate the oxidation reaction. The novel structure with an interface formed by a crystalline phase and an amorphous phase opens up a new approach to improve electrocatalytic activity.
近年来，具有核壳结构的纳米级 PtPb 催化剂因其出色的催化活性而受到广泛关注。我们报道了一类新型的 PtPb 纳米板（NP）催化剂，它通过离子辐照修饰实现了一种新颖的结构，其中包含一个同时以环形状态存在的晶相和非晶相界面。值得注意的是，具有新型结构的 PtPb NP 对甲醇氧化反应（MOR）表现出优异的催化活性。新型结构的 PtPb NPs 的比活性达到 4.32 mA cm-2，质量活性达到 1.31 A mg-1，分别是原始结晶态 PtPb NPs 的 1.9 倍和 1.4 倍。这种优异的催化活性可归因于离子辐照产生的具有特殊电子结构的晶相和非晶相界面的存在。密度泛函理论计算表明，这种新颖的界面激活了 C-H 和 O-H 键，从而提高了电催化活性，并优化了羟基和中间体在表面的吸附，促进了氧化反应。这种具有晶相和非晶相界面的新型结构为提高电催化活性开辟了一条新途径。
