The nature of K-induced 2H and 1T'-MoS species and their phase transition behavior for the synthesis of methanethiol (CHSH).

The one-step reaction approach from syngas with hydrogen sulfide (CO/H/HS) over potassium (K) promoted Molybdenum disulfide (MoS) materials can provide alternatives for the synthesis of methanethiol (CHSH). However, the direct confirmation and determination of the real active nature of K-induced 2H and 1T'-MoS for this reaction and the corresponding phase transformation behavior and origin of K-induced 2H-MoS from/to 1T'-MoS remains unclear. Herein, we proved at the atomic level the precise position of K over 1T'-MoS and 2H-MoS species using the technique of HAADF-STEM. A relationship between K-induced 1T' and 2H-MoS phases and the catalytic property to synthesize CHSH was established, and K-intercalated 1T'-MoS phase was confirmed to have excellent catalytic performances. Moreover, the behavior, origin, and influencing factors of phase transformation of 2H-MoS from/to 1T'-MoS in the existence of K were well proved.