Zhang Jia, Jin Hongmei, Sullivan Michael B, Lim Freda Chiang Huay, Wu Ping
Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632.
Phys Chem Chem Phys. 2009 Mar 7;11(9):1441-6. doi: 10.1039/b814647k. Epub 2009 Jan 19.
First-principles calculations were carried out to examine the catalytic activity of Pd and Pd-Au alloy surfaces for CO oxidation. The influences of surface-ligand effect and lattice strain effect on activity were demonstrated. The catalytic efficiency of Pd-Au bimetallic systems depends largely on the surface composition of Pd and Au. The addition of Au significantly improves the activity of a Pd-Au bimetallic slab with an Au-rich surface due to the dominant Au-induced ligand effect on both O and CO chemisorption. Among the various cases considered, the system with Au on the surface of the Pd(16)Au(4) slab exhibits the lowest energy barrier of 0.21 eV, which is decreased by 0.66 eV compared to that of the pure Pd(111) surface. It is predicted that the Pd core/shell nanoparticle catalyst should have a higher activity for CO oxidation as it combines the advantages of the ligand effect of Au and the strain effect of Pd.
进行了第一性原理计算，以研究钯和钯 - 金合金表面对一氧化碳氧化的催化活性。证明了表面配体效应和晶格应变效应对活性的影响。钯 - 金双金属体系的催化效率在很大程度上取决于钯和金的表面组成。由于金对氧和一氧化碳化学吸附的主导诱导配体效应，金的添加显著提高了具有富金表面的钯 - 金双金属板的活性。在所考虑的各种情况中，钯（16）金（4）板表面有金的体系表现出最低的能垒0.21电子伏特，与纯钯（111）表面相比降低了0.66电子伏特。据预测，[钯]（金）核壳纳米颗粒催化剂对一氧化碳氧化应该具有更高的活性，因为它结合了金的配体效应和钯的应变效应的优点。
