289f Predicting Catalytic Activity from Measured Electronic Structure of Supported Catalytic Materials: Supported Ni Versus Ni Alloys

Eranda Nikolla and Suljo Linic. Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109

It has been a long-standing goal of fundamental research in heterogeneous catalysis to establish universal relationships between electronic and geometric structure of catalysts and their chemical and catalytic activity. Recent theoretical work of Norskov and coworkers has led to the development of Norskov-Hammer d-band theory which has allowed us to relate the calculated electronic structure of transition and noble metals to their chemical activity. In its simplest form the d-band theory states that for a given surface adsorption site and geometry of an adsorbate, the adsorption energy of the adsorbate on the adsorption site depends on the position of the center of mass of d electrons (the d-band center) of the atoms that form the adsorption site. In general, those metals with the d-band center closer to the Fermi level are more chemically active than those with the d-band center further away from the Fermi level.

While there are a large number of contributions where DFT calculations have been utilized to validate the d-band theory, the experimental examples are scarce. In this contribution we demonstrate that a measured electronic structure, obtained using an arsenal of spectroscopic techniques, of supported Ni and Ni alloys can be related in a predictable fashion, consistent to the d-band theory, to the chemical activity and catalytic performance of these materials. While we present only the results for Ni-based catalytic materials, we believe that the conclusions presented herein are fairly universal for other transition and noble metals.