Slab Graph Convolutional Neural Network for Discovery of N2 Electroreduction Catalysts

The catalyst development for N2 electroreduction reaction (NRR) with low onset potential and high Faradaic efficiency is highly desired, but remains challenging. Machine learning (ML) recently emerged as a complementary tool to accelerate material discovery; however a ML model for NRR has yet to be developed. Here, we develop and report slab-graph convolutional neural network (SGCNN), an accurate and flexible ML model that is applicable to catalytic surface reactions. With the self-accumulated database of 2,699 surface calculations, SGCNN predict binding energies, ranging over 8 eV, of five key adsorbates (*H, *N2, *N2H, *NH, *NH2) related to NRR performance with the mean-absolute-error of only 0.23eV. Unlike previously available models, SGCNN avoids using ab initio level inputs, instead is solely based on elemental properties that are all readily available in Periodic-Table-of-Elements; true accelerations can be realized. t-distributed stochastic neighbor embedding (t-SNE) analysis reveals that binary intermetallics of averaged d-electron occupation between 4 and 5 could potentially lower the onset potential in N2 electroreduction.

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