State Key Laboratory Breeding Base for Green Chemistry Synthesis Technology, International Sci. & Tech. Cooperation Base of Energy Materials and Application, College of Chemical Engineering and Materials Science, Zhejiang University of Technology , 18 Chaowang Road, Hangzhou 310032, P. R. China.
Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen, 361005, P. R. China.
ACS Appl Mater Interfaces. 2017 Jun 21;9(24):20594-20602. doi: 10.1021/acsami.7b04419. Epub 2017 Jun 12.
Core-shell composites with strong phase-phase contact could provide an incentive for catalytic activity. A simple, yet efficient, HO-mediated method has been developed to synthesize a mesoscopic core-shell W@WC architecture with a dodecahedral microstructure, via a one-pot reaction. The HO plays an important role in the resistance of carbon diffusion, resulting in the formation of the W core and W-terminated WC shell. Density functional theory (DFT) calculations reveal that adding W as core reduced the oxygen adsorption energy and provided the W-terminated WC surface. The W@WC exhibits significant electrocatalytic activities toward hydrogen evolution and nitrobenzene electroreduction reactions, which are comparable to those found for commercial Pt/C, and substantially higher than those found for meso- and nano-WC materials. The experimental results were explained by DFT calculations based on the energy profiles in the hydrogen evolution reactions over WC, W@WC, and Pt model surfaces. The W@WC also shows a high thermal stability and thus may serve as a promising more economical alternative to Pt catalysts in these important energy conversion and environmental protection applications. The current approach can also be extended or adapted to various metals and carbides, allowing for the design and fabrication of a wide range of catalytic and other multifunctional composites.
核壳复合材料具有较强的相间接触，可为催化活性提供动力。通过一步反应，开发了一种简单而有效的 HO 介导方法，用于合成具有十二面体微结构的介观核壳 W@WC 结构。HO 在抵抗碳扩散方面起着重要作用，导致 W 核和 W 端 WC 壳的形成。密度泛函理论 (DFT) 计算表明，添加 W 作为核可降低氧吸附能，并提供 W 端 WC 表面。W@WC 对析氢和硝基苯电还原反应表现出显著的电催化活性，可与商业 Pt/C 相媲美，远高于介孔和纳米 WC 材料。实验结果通过基于 WC、W@WC 和 Pt 模型表面上析氢反应的能量曲线的 DFT 计算得到了解释。W@WC 还表现出较高的热稳定性，因此可能是这些重要的能量转换和环境保护应用中替代 Pt 催化剂的有前途的更经济选择。该方法还可以扩展或适用于各种金属和碳化物，从而可以设计和制造各种催化和其他多功能复合材料。
