LAUSR

A simple and effective strategy based on NH₄⁺ intercalation and thermal treatment was developed to tune the edge sites of MoS₂. The catalysts were characterized by X-ray diffraction, thermogravimetric, transmission electron microscopy-energy-dispersive X-ray, scanning electron microscopy, Raman spectroscopy, Brunauer–Emmett–Teller, X-ray photoelectron spectra, in situ Fourier-transform infrared (FT-IR) spectroscopy of NO adsorption, and CHNS elemental analysis. The intercalation of NH₄⁺ into the interlayers of MoS₂ with thermal treatment served to reduce numbers of stacking layers and generate edge-rich MoS₂ with disordered structures. An increase of NH₄⁺ intercalation resulted in a greater exposure of MoS₂ edges, which enhanced the conversion rate of CO in the methanation reaction. The FT-IR study of NO adsorption demonstrated that edge sites contributed to the catalytic activity. A decrease of the activity in the long-term (100 h) stability evaluation can be attributed to the sintering of MoS₂, the formation of MoO₂ with a loss of active MoS₂ components. This study established the intercalation of NH₄⁺ into the MoS₂ layers with subsequent heat treatment as an effective means to tune the edge sites and the catalytic activity.