Engineering Compressive Strain Gradients in 3D AuM Aerogels to Modulate Electrocatalytic Activity

Strain engineering has emerged as a powerful strategy for improving catalytic performance; however, controlling strain in three-dimensional architectures and clarifying its impact on electrocatalysis remain challenging. Here, we employ gold-based noble-metal aerogels as self-supported 3D frameworks to establish a graded series of compressive strain states across AuM aerogels. Incorporating Fe, Co, and Ni into Au aerogels, followed by acid etching, gives compressive strain values of 0.39, 0.56, and 0.69%, respectively, enabling the correlation of strain with electrocatalytic CO₂ reduction performance. AuNi aerogel achieves a current density of 85.6 mA cm⁻² at –0.66 V, with 97.4% CO selectivity and robust stability over 24 h. In situ analysis and theoretical calculations reveal that compressive strain upshifts the Au d-band center and strengthens *COOH adsorption to benefit the catalytic process. These findings establish a versatile strain-engineering strategy for 3D electrocatalysts, advancing the fundamental understanding and design of scalable, high-performance systems for sustainable energy conversion.