Efficient hydrodeoxygenation of guaiacol to phenol over Ru/Ti–SiO₂ catalysts: the significance of defect-rich TiO_x species

Abstract

Under relatively mild conditions (240 °C and 0.4 MPa H2), Ru/Ti–SiO2 exhibited higher activity for C–O bond cleavage compared with both Ru/SiO2 and Ru/TiO2 catalysts, and achieved high guaiacol conversion (83.6%) and phenol selectivity (70.4%).

Tuning Strong Metal‐Support Interactions for Enhancing Direct Deoxygenation of Biomass‐Lignin Derived Phenolics

“…[8,[14][15][16][17][18] It is generally believed that the interfacial perimeter site between metal and oxide plays a crucial role in such improved performance. [17,[19][20][21][22][23][24][25][26][27] Newman et al reported higher benzene selectivity during HDO of phenol on Ru/TiO 2 catalysts with small Ru size (1.5 nm) than large Ru size (33 nm), and ascribed this difference to the increased Ru-TiO 2 interfacial perimeter sites for smaller Ru size. [27] Lately, direct correlation between the deoxygenation activity and interfacial perimeter site was reported on Pt/Nb 2 O 5 and Ru/TiO 2 catalysts by assuming that the number of perimeter site is related with the metal particle size.…”

“…Combination of transition metal and reducible (oxophilic) metal oxide (for example, TiO 2 ) provides both hydrogenation and deoxygenation functionalities, and has shown higher activity and selectivity of DDO toward aromatics relative to metal on an inert support of SiO 2 [8,14–18] . It is generally believed that the interfacial perimeter site between metal and oxide plays a crucial role in such improved performance [17,19–27] . Newman et al.…”

Hydrodeoxygenation of guaiacol to phenol using endogenous hydrogen induced by chemo-splitting of water over a versatile nano-porous Ni catalyst

“…Typical temperatures are between 300 and 400 °C, with hydrogen pressures between 1 and 65 bar. [48][49][50][51][52] Mo based catalysts, in the form of oxides, phosphides, nitrides, and carbides, have been widely used for the catalytic demethoxylation reactions at 300-450 °C under 5-50 bar H 2 . [53][54][55][56][57][58][59] The MoN-A catalyst presented both high conversion (95%) and high selectivity (90%).…”

“…49,51,52 The use of precious metal catalysts, such as Ru/TiO 2 and Au/TiO 2 , has resulted in high guaiacol conversion (>80%) but relatively poor selectivity (70.4% and 49.6%) at 240-300 °C under 4-65 bar H 2 . 48,50 Compared with these systems, our system is the only one operating under "H 2free" conditions. In another case, despite Ru/C and Ni/CeO 2 -C being employed in the "H 2 -free" HDO of guaiacol, the yield of the target product catechol was extremely low (below 7%) at a higher temperature of 250 °C.…”

Biomass-Based Carbon Nanofibers Modified with Polyaniline for Supercapacitor Applications

“…Compared with the petroleum-based polymer as a precursor, the high value-added conversion of lignin can not only effectively improve the profits of the paper and biorefining industry but also effectively reduce costs and improve the renewability in the CNF field. − However, due to significant differences in the intrinsic chemical structure of lignin compared to that of other petroleum-based materials, the direct introduction of lignin through physical blending often seriously affects material properties during the preparation of high-value materials. Therefore, many strategies have been developed to chemically modify lignin macromolecules to meet the requirements of the corresponding high-value materials. − In our previous study, for the preparation of lignin-based hybrid electrodes, polyaniline segments were grafted onto lignin macromolecules, which could effectively reduce the phase separation between lignin macromolecules and polyaniline segments. The obtained polyaniline-/biomass-based CNFs exhibit the complete fibrous micromorphologies, large specific surface area, and excellent electrochemical energy storage performances .…”