(41a) A Theoretical Framework for Rapid Screening of Novel Multi-Metallic Alloy Catalysts

Multi-metallic alloys (MMAs) have sparked tremendous interest in discovering low-cost catalytic materials with high activity and selectivity in heterogeneous catalysis. MMA-based catalysts provide complementary functionalities and unprecedented tunability for novel catalyst designing. However, due to their immense structural and compositional complexity, investigating MMAs to find an optimal catalyst is a daunting and time-consuming process, both experimentally and theoretically. Therefore, designing new computational strategies to accelerate the screening of optimum catalysts across vast compositional space is highly desirable. This work introduces a simple and general method for predicting the site stability of MMA surfaces and nanoparticles spanning a wide-ranging combinatorial space. We parameterize the energy of constituent atoms as a function of their coordination number by performing a small handful of density functional theory (DFT) calculations of metal atom adsorption energies on clean and dilute bi-metallic alloy surface slabs. The obtained parameters are solely dependent on the identity and local coordination environment of a metal atom in both clean and diluted systems. By interpolating the obtained parameters from clean to completely diluted system, we can determine the stability of any given atom-site in any conceivable chemical environment across a wide range of morphologies, sizes, atomic compositions, and arrangements. We have validated our method across massive data sets by varying the elemental concentration of bi- and tri-metallic sets of Ir, Rh, Ru, Pd, and Pt and getting the high accuracy in predicting site stability, with errors between 0.11 and 0.15 eV (see figure). Our approach is highly efficient and easily transferrable to higher order of multi-metallic systems regardless of the percentage of the constituent elements. The approach only requires (N² •16) DFT calculations for MMAs composed of N elements. Our theoretical paradigm is robust in providing the atomic-level vision and accelerating the reverse engineering for emerging high entropy alloy catalysts.