CuxO-regulated multivalent Zn single-atom catalysts for selective α-C–C bond cleavage of fatty acids

Single-atom catalysts (SACs) are highly regarded for their high atomic efficiency and outstanding catalytic performance. However, the stable anchoring of single atoms and the precise regulation of their multiple valence states are still challenges. To address this challenge, a structurally stable and valence-tunable multivalent zinc single-atom catalyst was successfully synthesized according to a thermodynamically-driven lattice substitution strategy. Experimental and theoretical analyses indicate that zinc single atoms precisely occupy a pair of adjacent Cu + vacancies in the Cu 2 O lattice with a spacing of approximately 2.9 Å, forming Zn-O-Cu units. This structure establishes an electron transport channel mediated by oxygen bridges, facilitating strong electron coupling between the 3d orbitals of Zn and Cu. This strong coupling results in the formation of a stable multivalent Zn δ+ (0＜δ < 2) state, which is identified as the primary origin of the catalyst’s high activity. Benefiting from the unique electronic synergistic effect of the Zn-O-Cu units and the resulting promotion of oxygen vacancy formation, this catalyst enables carboxylic acid molecules to be adsorbed and activated in a bridging mode. Through this adsorption configuration, the α-C–C bond becomes polarized and significantly weakened, setting the stage for its selective cleavage. The Zn δ+ -O-Cu catalyst showed remarkable catalytic performance in the selective cleavage of the α-C–C bond in fatty acids for alkane production, achieving up to 96.89% n-C n-1 alkane selectivity. Furthermore, the Zn δ+ -O-Cu catalyst demonstrated excellent versatility across fatty acids with varying carbon chain lengths. These results demonstrate the significant promise of this strategy not only for advancing the practical utilization of biomass feedstock with high fatty acid (FA) content, but also for establishing an efficient and novel pathway toward long-chain alkane production.