Preparation and olefin-metathesis activity of cyclopentylidene-oxo initiator sites on a molybdenum carbide surface

Preliminary study of the surface reactivity of 2D α‐Mo2C crystallites

“…For example, Bauer et al report that benzene on monolayer molybdenum carbide displays C(1s) peaks at 284.0 and 284.5 eV, while cyclohexane displays a single peak at 284.8 eV . Furthermore, the CH 2 groups of cyclopentylidene on β‐Mo 2 C are characterized by a C(1s) binding energy of 284.7 eV . Hence, we conclude that the signal at 285.0 eV is mostly due to sp 3 carbon.…”

“…[38] Furthermore, the CH 2 groups of cyclopentylidene on b-Mo 2 C are characterized by a C(1s) binding energy of 284.7 eV. [40] Hence, we conclude that the signal at 285.0 eV is mostly due to sp 3 carbon.…”

“…This activation of the carbonyl group is revealed by DFT calculations for furfural on Mo 2 C/Mo(110), which predict that the CO bond is lengthened to 1.35 Åfrom its gas phase value of 1.23 Å. The h 2 (C,O)-bonded state is postulated to be an intermediate for deoxygenation, [46][47][48] as also found by Siaj et al for cyclopentanone [40] and cyclobutanone [49] on b-Mo 2 C. The peak at 531.1 eV in Figure 5b is thus attributed to oxygen in a di-sigma bonded, h 2 (C,O), configuration, by reference to O(1s) data for h 2 (C,O)-cyclopentanone on bulk b-Mo 2 C, where a peak at 530.9 eV was observed. [40] The present analysis of the XPS data for furfural on 2D-a-Mo 2 C/ Cu assumes that the signal primarily arises from species adsorbed on the molybdenum carbide crystallites.…”

“…The h 2 (C,O)-bonded state is postulated to be an intermediate for deoxygenation, [46][47][48] as also found by Siaj et al for cyclopentanone [40] and cyclobutanone [49] on b-Mo 2 C. The peak at 531.1 eV in Figure 5b is thus attributed to oxygen in a di-sigma bonded, h 2 (C,O), configuration, by reference to O(1s) data for h 2 (C,O)-cyclopentanone on bulk b-Mo 2 C, where a peak at 530.9 eV was observed. [40] The present analysis of the XPS data for furfural on 2D-a-Mo 2 C/ Cu assumes that the signal primarily arises from species adsorbed on the molybdenum carbide crystallites. This simplification is supported by DFT calculations by Xiong et al, [45][46][47] which predict that the adsorption energy of furfural is much greater on Mo 2 C than on Cu(111): 3.54 versus 0.22 eV.…”

ChemInform Abstract: Reaction Pathways of Biomass‐Derived Oxygenates over Metals and Carbides: From Model Surfaces to Supported Catalysts

“…Te chniques acetaldehyde b-Mo 2 CR AIS [101] acetaldehyde WC DFT, [14] TPD, [14] HREELS [14] acetaldehyde Zn/Pt(111)T PD, [17b] HREELS [17b] acetates Rh(111)H REELS, [102] TPD [102] acetic acid Re(0 001)D FT [103] acetic acid Pd(111)D FT [103] acetic acid Pd/ Re(0 001) DFT [103] acetic acid WC DFT, [14] TPD, [14] HREELS [14] acetone Mo 2 CD FT, [99] TPD [99] benzyl alcohol Pd(111)T PD, [38] HREELS [38] CO W(110)A ES, [104] TPD, [104] HREELS [104] CO C/W(110)A ES, [104] TPD, [104] HREELS [104] cyclohexanone Pt(111)T PD, [39] HREELS, [39] AES, [39] LEED, [39,105] DFT, [39] XPS, [105] GC [105] cyclopentanone b-Mo 2 CR AIS [106] dimethyl ether Rh(111)T DS, [107] HREELS [107] ethanol Co(0 001)D FT, [108] TP-XPS [108] ethanol K/Mo 2 C/ Mo(1 00) Work function, [109] TPD, [109] HREELS [109] ethanol Mo 2 C/ Mo(1 00) Work function, [110] TPD, [110] HREELS [110] ethanol Mo 2 CD FT, [4...…”