Understanding and Predicting the Reactivity and Selectivity for Formic Acid Decomposition on Au Nanoparticles

Formic acid decomposition (FAD) plays a significant role in the hydrogen economy, particularly in fuel cell technology, where Au nanoparticles (NPs) are among the best heterogeneous catalysts. These Au NPs not only offer high activity for H2 production but also tightly control the yield of CO, a byproduct from the side reaction. Theoretical studies of activity and selectivity at the nanoscale presents great challenges, especially when the selectivity of the side reaction is the primary concern. In this work, we utilize the enhanced extended phenomenological kinetics (XPK) method to investigate the impact of particle size on FAD over Au NPs. The simulation results provide a detailed examination of how particle size influences the reaction kinetics. Based on the enhanced XPK simulation results, simple kinetic models using the “generalized coordination number (GCN)” as descriptors are proposed. These models allow for the fast prediction of activity and selectivity of FAD on Au NPs of varying sizes. The enhanced XPK method and the kinetic models for fast prediction offer valuable insights into the size effects of metal NPs on catalytic activity and, in particular, selectivity, which can be useful for designing high-performance NP catalysts.