Unexpected Formation of Organic Siloxanes alongside Ethylphenols in the Catalytic Hydrogenation of Waste Enzymatic Lignin

TY - JOUR

T1 - Unexpected Formation of Organic Siloxanes alongside Ethylphenols in the Catalytic Hydrogenation of Waste Enzymatic Lignin

AU - Feng, Shanshan

AU - Liu, Xudong

AU - Fan, Jiajun

AU - Hu, Changwei

AU - Clark, James Hanley

N1 - © 2021 The Authors.

PY - 2021/10

Y1 - 2021/10

N2 - A multifunctional Ru/SBA-15 catalyst is prepared via impregnation and used in the depolymerization of crude waste corn stover enzymatic lignin (CSEL) to produce monophenols and, unexpectedly, the industrially important organic siloxanes. In the depolymerization of CSEL over Ru/SBA-15, a high phenolic monomer yield of 13.91 wt% with a high selectivity to ethylphenols (≈61%) can be achieved. Unexpectedly, when the reaction is carried out in ethanol, the predictable phenolic products are accompanied by both diethyl dimethyl orthosilicate and tetraethyl orthosilicate with the methyl group likely to come from lignin methoxy groups. Changing to a different alcohol solvent changes the siloxane products accordingly. The characterization of catalysts indicates that Ru0 is the active species in Ru/SBA-15 catalysts and is well dispersed with small particle size (6.2 nm). This catalyst significantly contributes to both the production of phenols and siloxanes and contributes to the hydrogenolysis/hydrogenation of lignin.

AB - A multifunctional Ru/SBA-15 catalyst is prepared via impregnation and used in the depolymerization of crude waste corn stover enzymatic lignin (CSEL) to produce monophenols and, unexpectedly, the industrially important organic siloxanes. In the depolymerization of CSEL over Ru/SBA-15, a high phenolic monomer yield of 13.91 wt% with a high selectivity to ethylphenols (≈61%) can be achieved. Unexpectedly, when the reaction is carried out in ethanol, the predictable phenolic products are accompanied by both diethyl dimethyl orthosilicate and tetraethyl orthosilicate with the methyl group likely to come from lignin methoxy groups. Changing to a different alcohol solvent changes the siloxane products accordingly. The characterization of catalysts indicates that Ru0 is the active species in Ru/SBA-15 catalysts and is well dispersed with small particle size (6.2 nm). This catalyst significantly contributes to both the production of phenols and siloxanes and contributes to the hydrogenolysis/hydrogenation of lignin.

U2 - 10.1002/aesr.202100059

DO - 10.1002/aesr.202100059

M3 - Article

SN - 2699-9412

VL - 2

JO - Advanced Energy and Sustainability Research

JF - Advanced Energy and Sustainability Research

IS - 10

M1 - 2100059

ER -