Pt-free Single-atom Catalysts (SACs) for the Enhanced ORR for Sustainable Hydrogen Fuel Cells

Atomically dispersed active sites have attracted great attention as a new frontier in the catalysis. Single-atom catalysts (SACs), well-defined mononuclear active sites, have demonstrated to be indispensable materials in catalysis. Both experimental and theoretical studies suggest that decreasing particle size is the most effective approach to improve the atom utilization and tune the physicochemical properties of these active centers, further leading to the enhancement of catalytic performances. Another advantage of the SACs is that the SACs have the ability to break away from the scaling relationship and this can lead to a high catalytic performance beyond the scaling relationship. Based on this concept, single-atom catalysts (SACs) have gained remarkable research interests due to their maximum atom utilization efficiency. Using a variety of fundamental understanding of their structure-property relations and electronic properties from density functional theory (DFT) calculations we will discuss the rational design and screen of single atom catalysts (SACs) based on low-dimensional macrocyclic molecules for the ORR catalysts for fuel cells applications. In this talk, we will also discuss a promising platinum-free cathode catalyst that effectively model the oxygen reduction reaction (ORR) of a proton-exchange membrane (PEM) fuel cell cathode better than the current commercial Pt/C catalyst has been a major shortcoming in cheaper fuel cell technology. Overall, the promising platinum-free cathode catalyst must offer great ORR activity, ORR selectivity, and acid stability will also be discussed.

Acknowledgments

This work used the Extreme Science and Engineering Discovery Environment (XSEDE) TACC at the stampede2 through allocation [TGDMR140131]. This work utilized resources from the University of Colorado Boulder Research Computing Group, which is supported by the National Science Foundation (awards ACI-1532235 and ACI-1532236), the University of Colorado Boulder, and Colorado. PCC Cluster, NM Consortium, NM.