Lanthanum-induced electronic structure modulation of Pt/Al₂O₃ for enhanced methylcyclohexane dehydrogenation

Methylcyclohexane (MCH), a representative liquid organic hydrogen carrier (LOHC), has attracted considerable attention for hydrogen storage and transportation, while its dehydrogenation efficiency remains a key factor limiting practical application. In this work, lanthanum-modified sub-nanometer Pt/Al₂O₃ catalysts were developed to regulate the interfacial electronic structure and enhance catalytic performance. The Pt/3La₂O₃-Al₂O₃ exhibits the best catalytic performance, delivering a hydrogen evolution rate of 2547 mmol·g_Pt^-1·min⁻¹ and maintaining a conversion above 99% over a 120 h long-time reaction. Structural characterizations indicate that La facilitates the formation of La-O-Al species, inducing strong interfacial electronic interactions and rendering the Pt surface electron-rich. Meanwhile, the introduction of La significantly decreases the amount of medium-strong acid sites. Density functional theory (DFT) calculations reveal that La-induced electron transfer downshifts the Pt d-band center, thereby weakening toluene adsorption. This suppresses deep dehydrogenation and coke formation. These results highlight the key role of interfacial electronic modulation in improving catalytic performance.