Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Angew Chem Int Ed Engl. 2017 Jul 17;56(30):8828-8833. doi: 10.1002/anie.201704632. Epub 2017 Jun 23.
Core-shell architectures offer an effective way to tune and enhance the properties of noble-metal catalysts. Herein, we demonstrate the synthesis of Pt shell on titanium tungsten nitride core nanoparticles (Pt/TiWN) by high temperature ammonia nitridation of a parent core-shell carbide material (Pt/TiWC). X-ray photoelectron spectroscopy revealed significant core-level shifts for Pt shells supported on TiWN cores, corresponding to increased stabilization of the Pt valence d-states. The modulation of the electronic structure of the Pt shell by the nitride core translated into enhanced CO tolerance during hydrogen electrooxidation in the presence of CO. The ability to control shell coverage and vary the heterometallic composition of the shell and nitride core opens up attractive opportunities to synthesize a broad range of new materials with tunable catalytic properties.
核壳结构为调节和增强贵金属催化剂的性能提供了一种有效的方法。在此，我们通过对母体核壳碳化物材料（Pt/TiWC）进行高温氨氮化，展示了在钛钨氮化物核纳米粒子（Pt/TiWN）上合成铂壳（Pt/TiWN）的方法。X 射线光电子能谱显示，负载在 TiWN 核上的 Pt 壳的芯层能级发生了显著位移，对应于 Pt 价 d 态的稳定性增加。通过氮化物核对 Pt 壳的电子结构进行调制，在存在 CO 的情况下，增强了氢电氧化过程中对 CO 的耐受性。通过控制壳层覆盖率以及改变壳层和氮化物核的杂原子组成，可以合成具有可调催化性能的广泛的新型材料，这为我们提供了有吸引力的机会。
