One-step synthesis of mesoporous alumina-supported molybdenum carbide with enhanced activity for thiophene hydrodesulfurization

Graphite Nanoflake-Modified Mo2C with Ameliorated Interfacial Interaction as an Electrocatalyst for Hydrogen Evolution Reaction

“…Meanwhile, the spectrum was dominated by a doublet with two sharp peaks located at 233.2 and 236.2 eV, which came from a Mo 6+ species (MoO 3 ). Beyond that, two pairs of peaks with binding energies of 233.5/230.3 and 235.1/232.0 eV corresponded to Mo 4+ species (MoO 2 ) and Mo 5+ species, respectively. , The Mo species with higher valences resulted from the surface oxidation of Mo 2 C, which is inevitable for Mo 2 C-based materials, especially for those with nanostructures. ,− ,, However, the surface oxidation has no negative influence on the electrocatalytic activity and even shows positive correlation with HER activity. − The C 1s spectrum (Figure d) of Mo 2 C/G-B presents a main peak at a binding energy of 284.8 eV associated with the presence of graphite nanoflakes (C–C), while the fitted peak at 285.7 eV is consistent with C–O species, which is usually detected in the carbon matrix. , The peak at a binding energy of 284.5 eV corresponding to the C–Mo bond is observed, proving electronic coupling at the interface between Mo 2 C quantum dots and graphite nanoflakes …”

“…The models of Mo 2 C clusters anchored on the basal planes of defect-free graphite are shown in Figure S5, in which the calculated hydrogen adsorption free energies (Δ G H* ) are −0.24, −0.18, −1.09, −0.59, −1.19, and 0.41 eV respectively for the different sites labeled in Figure S5a–f, while the calculated hydrogen adsorption free energies (Δ G H* ) of Mo 2 C anchored on the edges of graphite are −0.01, 0.66, 0.04, 1.25, 1.18, and 3.50 eV for different sites as presented in Figure S6a–f, respectively. The smaller absolute value of Δ G H* results, the more favorable HER thermodynamics . In general, the model of Mo 2 C anchored on the pore in the top layer of the basal plane of graphite stands out as a high-performance electrocatalyst for the HER, in which the Δ G H* values are competitive among the non-noble metal catalysts.…”

“…24,31 The Mo species with higher valences resulted from the surface oxidation of Mo 2 C, which is inevitable for Mo 2 C-based materials, especially for those with nanostructures. 1,[16][17][18]32,33 However, the surface oxidation has no negative influence on the electrocatalytic activity and even shows positive correlation with HER activity. 34−36 The C 1s spectrum (Figure 1d) of Mo 2 C/G-B presents a main peak at a binding energy of 284.8 eV associated with the presence of graphite nanoflakes (C−C), while the fitted peak at 285.7 eV is consistent with C−O species, which is usually detected in the carbon matrix.…”

Perspectives on strategies for improving ultra-deep desulfurization of liquid fuels through hydrotreatment: Catalyst improvement and feedstock pre-treatment

“…desirable electronic and magnetic properties, extreme hardness, and ionic charactericsts (Chen, 1996). However, they have additional advantages of being resistant to sintering at high temperatures, having strong interactions with nitrogen, sulfur and other heteroatoms in fuel and not causing C-C bond scission which leads to undesirable saturation of aromatics (Lin et al, 2021;Yue et al, 2021). They also have noble metal-like properties that make them effective hydrogenation catalysts (Yue et al, 2021).…”

“…However, they have additional advantages of being resistant to sintering at high temperatures, having strong interactions with nitrogen, sulfur and other heteroatoms in fuel and not causing C-C bond scission which leads to undesirable saturation of aromatics (Lin et al, 2021;Yue et al, 2021). They also have noble metal-like properties that make them effective hydrogenation catalysts (Yue et al, 2021). However, transition metal carbides and nitrides do not sustain long-term stability, they are easily deactivate due to their strong affinity with the adsorbates, especially at high temperatures (Lin et al, 2021).…”