The performance of alloys largely depends on their microstructures. With the rapid development of nanotechnology, nanoclusters, as a special form of bimetallic alloys, have garnered extensive attention from researchers [
71,
72]. For instance, Jäger
et al. [
73] utilized the Kernel Ridge Regression (KRR) ML model to predict the
EH, ads values on AuCu nanoclusters. As shown in
Fig. 3, by comparing various structural descriptors such as atom-centered symmetry functions (ACSF), many-body tensor representation (MBTR), and smooth overlap of atomic positions (SOAP), they examined how different representations influence model performance.
Figs. 3a and
b showed that as the size of the training set increases, the RMSE of all models decreases significantly, with the SOAP descriptor performing the best on larger datasets.
Figs. 3c–
e further illustrate that the SOAP descriptor is particularly sensitive to the local environment, provided the most accurate predictions for larger datasets. Furthermore, increasing the size of the training set continuously improved the prediction accuracy, highlighting the benefits of larger datasets in enhancing ML model performance. This work not only improved the accuracy of predicting catalytic active site
EH, ads, but also reduced the costs of modeling. Subsequently, they expanded their research to include bimetallic alloys of various shapes and sizes.
Fig. 4a showed an automated workflow that systematically progresses from the generation of nanoclusters to the submission of production jobs, and finally to the prediction of
EH, ads, achieving efficient structure screening and performance evaluation [
74].
Fig. 4b demonstrated the excellent prediction accuracy, showing good agreement between the predicted values and DFT calculation results.
Fig. 4c illustrated the distribution characteristics of
EH, ads for different binary combinations: some combinations exhibit convex behavior, indicating that the mixed cluster is less favorable than the pure components, while others show concave behavior, suggesting synergistic effects at certain compositions.
Fig. 4d further analyzed the impact of surface reconstruction and adsorption site drift on the prediction results, revealing that these factors have minimal effect on model accuracy. The results also show that the maximum value of the d-band Hilbert transform
εu is closely related to the
EH, ads at the nanocluster level, which can be used as a screening feature available at the nanocluster level. In 2021, Mao
et al. [
75] investigated clusters with core-shell structured clusters. They optimized and evaluated 7924 Cu
55-nM
n (M = Co, Ni, Ru, Rh,
n ≤ 22) alloy clusters and found that the CuNi alloy clusters exhibited superior HER activity, with the active sites mainly located at the bridging and triple sites of the shell Cu atoms. Moreover, they defined a surface charge-based descriptor, Δ
QCu−Cu, which effectively assesses the HER activity of alloy clusters by calculating the average charge difference between surface atoms of the clusters. As shown in
Figs. 5a and
b, the Δ
QCu−Cu values on Cu
55-nM
n alloy clusters vary with increasing dopant concentration. Each type of Cu
55-nM
n alloy cluster exhibits a maximum Δ
QCu−Cu value, and there is an approximately linear relationship between Δ
QCu−Cu and the number of active sites on the Cu
55-nM
n clusters. A ML NN trained on a large DFT database using this descriptor can rapidly and accurately predict Δ
GH∗ values on nanocluster surfaces. As shown in
Figs. 5c and
d, the model achieves MAE of 0.07 eV and RMSE of 0.11 eV on the test set. This study promotes the application of high-throughput computational method in the field of electrocatalyst design. In the latest research, Kang
et al. [
76] employed an machine learning potential (MLP) model to conduct annealing MD simulations, revealing the structure of ligand-free AuPt nanoclusters. Through these simulations, they found that Au atoms tend to segregate to the surface, forming a Pt(core)/AuPt(shell) structure. By investigating the interactions between Au and Pt, they found that when the Au content is low, Au atoms enhance the hydrogen adsorption on the adjacent Pt atoms. This enhancement is attributed to the altered electronic structure of Pt caused by the presence of Au, leading to stronger hydrogen binding.