Regensburg 2022 – wissenschaftliches Programm
O 3.1: Topical Talk
Montag, 5. September 2022, 10:30–11:00, H4
Rational design of single atom electrocatalysts: handle with care — •Gianfranco Pacchioni — Dipartimento di Scienza dei Materiali, Università Milano-Bicocca, Milano, Italy
One of the objectives of electronic structure theory is to predict chemical and catalytic activities. This is a challenging target due to the large number of variables that determine the performance of a heterogeneous catalyst. The complexity of the problem has reduced considerably with the advent of single atom catalysts (SAC) and, in particular, of graphene-based SACs for electrocatalytic reactions such as the oxygen reduction (ORR), the oxygen evolution (OER) and the hydrogen evolution (HER) reactions. In this context we assist to a rapidly growing number of theoretical studies based on density functional theory (DFT) and of proposals of universal descriptors that should provide a guide to the experimentalist for the synthesis of new catalysts. In this talk we critically analyze some of the current problems connected with the prediction of the activity of SACs based on DFT: accuracy of the calculations, neglect of important contributions in the models used, physical meaning of the proposed descriptors, inaccurate data sets used to train machine learning algorithms, not to mention some severe problems of reproducibility. It follows that the 'rational design' of a catalyst based on some of the proposed universal descriptors or of the DFT screening of large number of structures should be considered with great caution.