Investigating the influence of atomic-scale self-limiting stress in CuAg@NiAg nanoparticle on CO₂ electroreduction...

Whether stress at the micro-structural level exhibited self-limiting characteristics similar to macroscopic conditions, thus affecting the performance of catalysts in relation to the scope of stress influence, remained a topic requiring further investigation. In this study, we designed a CuAg@NiAg core-shell structure to induce lattice expansion and generate stress at the core-shell interface through the simultaneous action of displacement and co-reduction reactions. By adjusting the shell thickness, we investigated the impact of atomic-scale stress influence range (self-limiting behavior) on catalytic performance. The results indicated that with a thinner shell, stress had a greater influence on the surface, leading to excellent selectivity for CH₄ and C₂， achieving a methane Faradaic efficiency (FE) of 51.2 % at -0.9 V vs. RHE, and a C₂ product FE of 21.6 % at -1.1 V vs. RHE. Conversely, a thicker shell resulted in weaker surface effects due to the self-limiting behavior of stress, the observed enhancement in catalytic performance could only be attributed to the influence of the core-shell effect. This work provided insights for the study of catalyst stress engineering at the micro-scale.