Extended Data Fig. 4: Structure-activity relationship of different MoS2 catalysts.
From: Sulfur vacancy-rich MoS2 as a catalyst for the hydrogenation of CO2 to methanol
a–d, HRTEM images of the FL-MoS2 (a), ML-MoS2 (b), TL-MoS2 (c) and Bulk-MoS2 (d), respectively. e–g, Layer number statistics for at least 100 of MoS2 layers of the FL-MoS2 (e), ML-MoS2 (f) and TL-MoS2 (g), respectively, based on the HRTEM images. h, XRD patterns of different MoS2 catalysts. These MoS2 catalysts exhibit a typical hexagonal 2H-MoS2 crystal, corresponding to PDF #37-1492. i, Correlations between the intensity ratio of the XRD (002) and (100) peaks (I(002)/(100)) and the layer thicknesses of different MoS2 catalysts. Error bars represent the standard deviation for statistical layer numbers of different MoS2 catalysts, respectively. The I(002)/(100) of MoS2 had been reported to assess the variation of layer numbers in a series of MoS2 materials80. The increasing trend of I(002)/(100) values of the FL-MoS2 (0.78), ML-MoS2 (1.12), TL-MoS2 (1.76) and Bulk-MoS2 (8.77) indicate the increasing layer numbers of these MoS2 catalysts. j, In-situ EPR spectra of H2-pretreated MoS2 samples (see Methods for more details). k, The correlation between the rf for methanol formation and the density of single electron for the MoS2 catalysts. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) was used as an external standard to estimate the density of sulphur vacancies. l, BET surface area of different MoS2 samples. m, The correlation between the rf for methanol formation and the BET surface area of the MoS2 catalysts. n, The 31P MAS NMR spectra of in-situ H2-pretreated MoS2 samples after full adsorption of TMP. The black lines are raw data and red lines are fitting results. o, The correlation between the rf for methanol formation and the specific adsorption capacity of TMP for the MoS2 catalysts. p, CO2 hydrogenation performances and TMP adsorption capacities of different MoS2 catalysts. Catalysts were pretreated in-situ by H2 at 300 °C for 3 hours. Reaction activity tests were performed at 3000 mL gcat.−1 h−1, 180 °C, 50 bar and H2/CO2 ratio of 3:1.
