The dissociative chemisorption of NO, N2, and O2 on close-packed, stepped, and kinked surfaces of transition metals have been studied using density functional theory. We analyze the trends in chemisorption energies and transition state energies when going from one metal to the next and from one surface facet to the next. The Br�nsted-Evans-Polanyi relations show that the {111} surface facet is intrinsically the least reactive and that the {110} surface is the most reactive of the investigated facets. The surface facet dependent variation in catalytic activity has then been studied for the direct NO decomposition reaction by solving the differential equations of a microkinetic model in the steady state numerically. Going from a closedpacked facet to a more open facet the activity increases by up to a factor of 105. The various open facets (here limited to the {100}, {110}, {211}, {311}, and {532} facets), however, generally exhibit very similar catalytic activities, lending credibility to the use of any one of them as a model for a general under-coordinated surface site. We compare the microkinetic model of the NO decomposition rate of the pure metals obtained from a full description of the energetics with one obtained from scaling (reducing the number of independent variables from 7 to 2), and we show that even if the scaling relations do introduce some uncertainty, the overall ordering of the metals' catalytic activity is well-represented by the scaling relations. The kinetic models for the different surface facets are then coupled together through the use of free-energy based Wulff constructions in order to model the large-scale particle limit of the activity of the pure elemental metals.1,2,31H. Falsig et al., Top. Catal. In press (2013)2T. Khan et al., Submitted3S. Brodersen et al., In preparation

Electronic structure analysis of the trends in direct NO decomposition

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.