Enabling Generalized Coordination Numbers to Describe Strain Effects.

The world's growing energetic demand calls for efficient generation and interconversion of different types of energy. Heterogeneous catalysis can help cope with such demand, provided that rational, accurate and affordable design methods lead to the discovery of cost-effective and efficient catalysts. Here we derive a simple descriptor to simultaneously capture two parameters commonly used in catalytic materials design: strain and coordination. We test the descriptor with four different adsorbates on four active sites of two metals, and applying strain in the range of ±3 %, usually observed experimentally at catalytic metal surfaces. Furthermore, we use the descriptor to illustrate catalyst design availing strain and nearest-neighbor effects simultaneously for the oxygen reduction reaction, a reaction of high importance in fuel cells. The connection between coordination and strain helps in the search for robust yet rapid catalyst design methodologies.