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• Ultrasound induced impregnation assisted via microwave heating was applied. • Supported few-layers and ordered MoS 2 nanosheets was synthesized. • Methyl mercaptan synthesis from CO and H 2 S was selected as test reaction. • The performance is much higher for the present than for the literature catalysts. • MoS 2 nanosheet layers and K doping are essential, but the former is dominating. Supported MoS 2 based materials are widely used as heterogeneous catalysts. In this work, we propose a rapid and facile method (ultrasound-induced impregnation assisted by microwave thermal treatment) to synthesize mesoporous silica (SBA-15)-supported, few-layer, ordered and K-promoted MoS 2 nanosheets with different K/Mo ratios. The prepared catalysts are characterized by various physical and chemical techniques. Their catalytic performance is evaluated by methyl mercaptan (CH 3 SH) synthesis from CO/H 2 /H 2 S. The results show that our catalysts exhibit a much higher CO conversion and selectivity to CH 3 SH than the catalysts prepared using the conventional impregnation and reported in the literature. The good performance arises because of two main factors: MoS 2 nanosheets of only 2–4 layers and K promotion. Experimental characterizations and (density functional theory) calculations show that the former is the typical nano-size effect, and the latter stabilizes C S bonds when activating COS molecules. [ABSTRACT FROM AUTHOR]

• Collaborative removal and recycling treatment of CO and H 2 S into CH 3 SH is promising. • MSI, SMSI and EMSI are constructed and investigated for the synthesis of CH 3 SH. • SMSI favors the production of smaller sizes of K-MoS 2 particles and enhances the CH 3 SH formation rate. • EMSI is not in favor to the synthesis of CH 3 SH from CO/H 2 /H 2 S mixtures. Modulation of the metal-support interactions (MSI) is an effective means to improve the performance of supported catalysts, but the role of the metal-support effect in the synthesis of CH 3 SH from CO/H 2 /H 2 S mixtures has not been recognized. Here, three different interactions, namely weak MSI, strong MSI and electronic MSI are constructed over K-promoted MoS 2 -base catalysts and investigated for the synthesis of CH 3 SH. The catalytic activity experiments show that the K-Mo catalyst with strong MSI has the highest formation rate toward CH 3 SH, while the K-Mo catalyst with electronic MSI instead shows the worst formation rate toward CH 3 SH. The characterizations suggest that the strong MSI facilitates the enhancement of Mo-S bond strength and the production of few layers, shorter slab and ordered K-MoS 2 particles. The former benefits the formation and stabilization of C-S intermediate species and subsequent hydrogenation to CH 3 SH, while the latter promotes the generation of more Mo-coordinatively unsaturated sites (Mo-CUS) and thus facilitates the first-step adsorption and activation of reactants. In contrast, electronic MSI weakens the strength of the Mo-S bond, which inhibits the generation of C-S intermediate species. On the other hand, the presence of electronic MSI leads to the generation of Mo-O v -Ti interfacial sites, which is favorable for the hydrogenolysis of CH 3 SH to CH 4. This work provides an insight into the construction and selection of metal-support interactions for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

The cooperative transition of sulfur-containing pollutants of COS/H 2 S/H 2 to the chemical feedstock of methyl mercaptan (CH 3 SH) catalyzed by Mo-based catalysts has good application prospects. However, the role of rare earth elements as promoters in this reaction system has not been investigated currently. In this study, the effects of the rare earth of lanthanum (La) on the catalytic performance of Mo-based catalysts were investigated by XRD, Raman, TEM, H 2 -TPR, and XPS characterizations. The results showed that the addition of La species led to the formation of larger particle size and lower sulfidation degree of Mo species, but the higher, rather than lower, catalytic activity was obtained. This unusual phenomenon is confirmed to be due to the generation of La 2 (MoO 4) 3 crystals covered with surface MoS 2 layers caused by the interaction of Mo oxide and La species at the sulfidation atmosphere. The presence of La 2 (MoO 4) 3 changes the electronic and chemical environment of MoS 2 in the catalyst, which lead a positive effect on the catalytic activity, outweighing the negative effect caused by the larger particle size of Mo species and the reduced sulfidation. [Display omitted] • The collaborative removal of COS/H 2 S/H 2 into high added-valuable of CH 3 SH is promising. • The addition of La results in the formation of La 2 (MoO 4) 3 and the surface MoS 2 layer. • La affect the sulfidation, particle size, and electronic properties of Mo-based catalysts. • Beneficial electronic effect is the main reason for the enhanced catalytic performance. [ABSTRACT FROM AUTHOR]