Structural Modulation of Pt Nanoparticles Anchored by NiO _<i>x</i> on Silica for Enhanced Methylcyclohexane Dehydrogenation

Liquid organic hydrogen carriers represent a promising strategy for advancing the development of hydrogen-based energy systems. However, the catalytic dehydrogenation performance of cycloalkanes on Pt-based catalysts is intrinsically limited by a trade-off between reactant activation and aromatic products desorption. The strongly adsorbed products prove detrimental and require enhancement of desorption without activity loss. Here, we synthesized thermally stable Pt nanoparticles immobilized by uniformly distributed NiOx species on fumed SiO2. For methylcyclohexane dehydrogenation, the stabilizing role of NiOx cluster-modified SiO2 combined with hydrogen-carrier-gas-assisted toluene desorption ensured the long-term stability of Pt nanoparticles. Furthermore, the optimized NiOx–Pt interaction generated partially positively charged Pt species, facilitating C–H activation. The synthesized PtNi1/SiO2 exhibited a hydrogen production rate of 58.9 mmolH2 gcat–1 min–1 with high toluene selectivity (>99%) at 350 °C. It remained stable for over 2400 min through intermittent regeneration under a high weight hourly space velocity of 50 h–1. This work demonstrates the rational design of thermally stable metal nanoparticles and provides mechanistic insights into suppressing dehydrogenation and catalyst deactivation.