Selecting the Most Suitable DFT-XC Functional for Consistent Modeling of Subnanometric Gold Clusters in Catalytic Systems

A comprehensive analysis of selected DFT exchange–correlation functionals is presented, focusing on their performance in treating gold nanoclusters and on their known reliability for the description of organic species, energy barriers and dispersion interactions. To distinguish this study from the existing literature, the investigation specifically considers the practical relevance of the chosen functionals in catalytic contexts, with a particular emphasis on their potential applications in nanocatalysis for biomass valorization. Gold clusters containing 4 to 20 atoms were examined, with special attention given to the number of atoms at which the planar-to-three-dimensional-structure switch occurs. The investigation reported in this work would suggest M06 as the best exchange–correlation functional in terms of applicability and overall accuracy for computational studies of catalyzed processes involving gold nanoclusters and organic components.