ABSTRACT This study introduces a quasi‐homogeneous catalytic strategy employing exfoliated transition‐metal hydroxide nanosheets (M(OH) x NS) for the efficient hydrogenation of 4‐nitrophenol. NaBH 4 treatment dramatically induced the fast boron‐incorporation into the M(OH) x NS—a process not observed on bulk M(OH) x . The B‐doped cobalt hydroxide nanosheets (Co(OH) x ·B) exhibit remarkable catalytic performance by maximizing nanosheet dispersion in solution and enabling regeneration of active sites. Notably, Co(OH) x ·B achieves a high activity factor of 7197 s −1 g −1 , significantly outperforming the c ‐Pt/C catalysts (248 s −1 g −1 ). It also showed an apparent rate constant of 0.57 min −1 and a turnover frequency of 129.55 mmol gCo −1 min −1 , surpassing bulk Co(OH) 2 , Co 2 B, and even c ‐Pt/C. To elucidate the origin of this high catalytic efficiency, Raman spectroscopy revealed that the boronation process partially reduces Co 2+ to Co δ+ within the Co(OH) 2 NS, accompanied by the removal of lattice –OH. The partial reduction generates coordinatively unsaturated Co δ+ sites that favor hydride (H − ) adsorption, thereby promoting hydrogenation. These findings highlight how boronation‐induced electronic modulation enhances catalytic activity by creating distinct active sites. The 2D structure, bridging robust heterogeneous and accessible homogeneous catalysis, renders the mechanism broadly applicable. These findings elucidate boronation‐induced electronic modulation and establish a general design principle for integrating heterogeneous and homogeneous catalysis using 2D nanosheets.
Kwon et al. (Sun,) studied this question.