Highly Stable Nb₂O₅–Al₂O₃ Composites Supported Pt Catalysts for Hydrodeoxygenation of Diphenyl Ether

Abstract

Various TiO2, SiO2, Al2O3, and Nb2O5–Al2O3 supported Pt catalysts have been prepared by urea precipitation method for catalytic hydrodeoxygenation (HDO) of diphenyl ether (DPE) as a 4-O-5 aryl-ether lignin model compound. The selectivity toward deoxygenated product cyclohexane increased obviously with Nb2O5·nH2O decorated, owing to the significant promotion effect of NbO x species and acid sites on C–O bond cleavage. At higher pressure (3.0 MPa H2), DPE underwent a HYD route, while direct hydrogenolysis route occurred at low pressure (0.1 MPa H2). In addition, the reaction rate constants and activation energies were obtained in the temperature range from 160 to 220 °C. Based on the Arrhenius law, the activation energy for the cleavage of the C–O bond in DPE was calculated to be 91.22 kJ/mol. It was noteworthy that the Pt/20Nb–Al2O3 showed higher stability than Pt/Al2O3 for hydrodeoxygenation of diphenyl ether, which can be attributed to its water-tolerant Lewis acid sites.

One‐step Modification of Active Sites and Support in Ni/Al2O3 Catalyst for Hydrodeoxygenation of Lignin‐derived Diphenyl Ether

“…The conversion of DPE and selectivity to different product are shown in Table S2. The Ni/20NbAC, MoC x /C, and Pt/20Nb−Al 2 O 3 show a high selectivity to BEN at low H 2 pressure. While the selectivity to O‐free product is much lower than the Ni 2 Si/SiO 2 ‐Al 2 O 3 catalysts.…”

Advances in porous and nanoscale catalysts for viable biomass conversion

“…On the other hand, supported Pt based catalysts (TiO 2 , SiO 2 , Al 2 O 3 , and Nb 2 O 5 -Al 2 O 3 ) displayed good activity in the vapour-phase HDO of diphenyl ether. 397 The 0.40 wt% Pt/20Nb-Al 2 O 3 catalyst afforded 100% diphenyl ether conversion and 99.2% cyclohexane selectivity due to the presence of abundant water-tolerant Lewis acid sites (entry 10, Table 2). Bimetallic NiCo/g-Al 2 O 3 catalysts were found to be promising in the aqueous phase HDO of guaiacol compared to supported monometallic Ni and Co catalysts.…”

Effects of reaction conditions on catalytic hydroconversion of phenethoxybenzene over bifunctional Ni/Hβ

“…Due to the structural complexity of lignin, dimeric lignin model compounds representing C–O linkages in lignin have been studied to investigate the CHC mechanism at molecular level . Among various model compounds, phenethoxybenzene (POB), which represents β‐O‐4 linkage that is the dominant linkage in lignin, has been widely used as a lignin model compound for studying the CHC mechanism .…”

“…[6][7][8][9] Due to the structural complexity of lignin, dimeric lignin model compounds representing C-O linkages NOMENCLATURE: BR, benzene ring; CEOB, (2-cyclohexylethoxy)benzene; CEOC, (2-cyclohexylethoxy)cyclohexane; CH, cyclohexane; CHC, catalytic hydroconversion; CHEB, (2-cyclohexylethyl)benzene; CHEL, 2-cyclohexylethanol; CHL, cyclohexanol; COEB, (2-(cyclohexyloxy)ethyl) benzene; DCHE, 1,2-dicyclohexylethane; EB, ethylbenzene; ECH, ethylcyclohexane; GC-MS, gas chromatography/mass spectrometry; IHP, initial H 2 pressure; PEL, 2-phenylethanol; 2-PEP, 2-phenethylphenol; 4-PEP, 4-phenethylphenol; POB, phenethoxybenzene; SSA, specific surface area; TPV, total pore volume in lignin have been studied to investigate the CHC mechanism at molecular level. 4,[18][19][20] Among various model compounds, phenethoxybenzene (POB), which represents β-O-4 linkage that is the dominant linkage in lignin, has been widely used as a lignin model compound for studying the CHC mechanism. 6,21-23 Zhao et al 6,22 found that the reaction route of POB over Ni/HZSM-5 or Pd/C and HZSM-5 proceeded through metal-catalyzed C-O bridged bond cleavage followed by sequential hydrogenation and dehydration reactions to remove oxygen atoms in aqueous phase.…”