Hefei National Laboratory for Physical Sciences at the Microscale, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), School of Chemistry and Materials Science, Hefei Science Center (CAS), and National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
Chemistry. 2018 Dec 10;24(69):18398-18402. doi: 10.1002/chem.201803267. Epub 2018 Oct 4.
Metal-containing nanocrystals with well-designed surface structures represent a class of model systems for revealing the fundamental physical and chemical processes involved in heterogeneous catalysis. Herein it is shown how surface modification can be utilized as an efficient strategy for controlling the surface electronic state of catalysts and, thus, for tuning their catalytic activity. As model catalysts, the Pd-tetrahedron-TiO nanostructures, modified on the surface with different foreign atoms, showed a varied activity in the catalytic decomposition of formic acid towards H production. The catalytic activity increases with a reduction in the work function of modified atoms; this reduction can be well explained by a surface polarization mechanism. In this hybrid system, the difference in the work functions of Pd and modified atoms results in surface polarization on the Pd surface and, thus, in the tuning of its charge state. Together with the Schottky junction between TiO and metals, the tuned charge state enables the promotion of catalytic efficiency in the catalytic decomposition of formic acid to H and CO .
具有精心设计表面结构的含金属纳米晶体是一类用于揭示多相催化中涉及的基本物理和化学过程的模型体系。本文展示了如何利用表面修饰作为一种有效的策略来控制催化剂的表面电子态，从而调节其催化活性。作为模型催化剂，表面用不同的外来原子修饰的 Pd-四面体-TiO 纳米结构在甲酸催化分解制氢反应中表现出不同的活性。催化活性随修饰原子的功函数降低而增加；这种降低可以用表面极化机制很好地解释。在这个混合体系中，Pd 和修饰原子的功函数差异导致 Pd 表面的表面极化，从而调节其电荷态。与 TiO 和金属之间的肖特基结一起，调谐的电荷态能够促进甲酸催化分解制 H 和 CO 的催化效率。
