fig5
Figure 5. (A) In situ ED-XAS: (a and b) coupling in situ DRIFTS; (c and d) characterizations of ER-MoS2-K during H2 pretreatment measured with a hyphenated technology. Relative intensity in (a) was obtained by subtracting each spectrum from the first spectrum. (e) In situ DRIFT spectra of CO hydrogenation over the H2-pretreated catalysts at 25 °C, H2/CO of 2 and 1 bar. (f) Arrhenius plots calculated based on the reaction rate for methanol hydrogenation over PD-MoS2-K and ER-MoS2-K. (g) In situ DRIFT spectra of CO hydrogenation over the H2-pretreated catalysts at 240 °C, H2/CO of 2 and 30 bar. (h) In situ SVUV-PIMS detection of the CO hydrogenation intermediates and products over the H2-pretreated catalysts at 240 °C, H2/CO of 2 and 5 bar. (i) Quasi in situ SRPES detection of the CO hydrogenation intermediates. SRPES spectra were obtained after the treatment of the H2-treated catalysts with reaction gas (H2/CO = 2) at 240 °C and 5 bar for 0.5 h. (j) Proposed reaction mechanism for CO hydrogenation to methanol and ethanol on edge and in-plane sites of MoS2. (A) is reprinted with permission from Ref.[106], Copyright © 2023 Springer Nature; (B) Schematic diagram of Mo2C surface. (a) Mo0, (b) carbon defects and (c) Mo defects. (B) is reprinted with permission from Ref.[111], Copyright © 2021 MDPI; (C) Schematic of catalyst synthesis process and its performance for RWGS reaction. (C) is reprinted with permission from Ref.[113], Copyright © 2024 The American Association for the Advancement of Science; (D) Transformations of Mo/NC and Ni-Mo/NC catalysts after H2 reduction and DRM reaction. (D) is reprinted with permission from Ref.[114], Copyright © 2025 WILEY. RWGS: Reverse water-gas shift; ED-XAS: Energy-dispersive x-ray absorption spectroscopy; DRIFTS: diffuse reflectance infrared fourier-transform spectroscop; DRM: dry reforming of methane; NC: nitrogen-doped carbon; SRPES: synchrotron-radiation photoelectron spectroscopy.
