From structure prediction to catalyst design: 2D MoS₃ as tunable platform for CO₂ electroreduction

Utilizing the advanced crystal structure prediction algorithm CBD-GM, this study reports the first prediction of a novel 2D MoS₃ configuration. The results demonstrate that the monolayer MoS₃ exhibits excellent structural and thermal stability, narrow-bandgap semiconductor behavior, high carrier mobility, and pronounced mechanical anisotropy, highlighting its potential for applications in flexible electronics. Building upon this foundation, we designed a series of single-atom catalysts by anchoring transition metal atoms at distinct sulfur coordination sites (S₁, S₂, S₃) of the MoS₃ support. This work reveals that both the dopant element and its coordination site precisely regulate the catalytic activity and selectivity for the CO₂ reduction reaction (CO₂RR). Theoretical screening identified three highly promising candidates: Sc_S2@MoS₃, Sc_S3@MoS₃, and Ni_S3@MoS₃. Sc_S2@MoS₃ favors the formate pathway to HCOOH with a low limiting potential of -0.18 V. Sc_S3@MoS₃ exclusively produces CH₃OH with a rate-determining step of *CHO → *OCHH (U_L = -0.58 V). Ni_S3@MoS₃ can generate both HCOOH (U_L = -0.55 V) and CH₃OH (U_L = -0.72 V) under different potentials. Notably, Sc_S3@MoS₃ exhibits the lowest reaction energy for methanol formation. This study provides crucial theoretical guidance for developing efficient and tunable CO₂ electrocatalysts and expands the Mo-S material family by introducing a metastable but accessible 2D MoS₃ platform with unique coordination environments for single-atom catalysis, thereby broadening the application potential of 2D materials in energy conversion and environmental remediation.