Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Mild reductive catalytic depolymerization of lignin in a continuous flow reactor using a Cu-enhanced Pd catalyst

De Saegher, Tibo LU ; Elmroth Nordlander, Jonas LU ; Hallböök, Filip LU ; Atanasova, Boyana ; Vermeir, Pieter ; Van Geem, Kevin M. ; De Clercq, Jeriffa ; Verberckmoes, An ; Hulteberg, Christian LU orcid and Lauwaert, Jeroen (2025) In Chemical Engineering Journal Advances 22.
Abstract

Mild reductive catalytic depolymerization (MRCD) of lignin offers a sustainable route to produce functionalized aromatic compounds. However, the economic viability is hindered by the need for expensive palladium (Pd) catalysts and the limited exploration of continuous flow reactors (CFRs), which are essential to achieve an adequate production scale. This study examines the impact of partial replacement of Pd with copper (Cu) on the performance, selectivity, active site characteristics, and deactivation of a γ-Al2O3 supported Pd catalyst in MRCD of lignin using a CFR. Despite containing 49 % less Pd, the PdCu catalyst achieves the same depolymerization degree as the Pd catalyst over 200 min of time on stream. During... (More)

Mild reductive catalytic depolymerization (MRCD) of lignin offers a sustainable route to produce functionalized aromatic compounds. However, the economic viability is hindered by the need for expensive palladium (Pd) catalysts and the limited exploration of continuous flow reactors (CFRs), which are essential to achieve an adequate production scale. This study examines the impact of partial replacement of Pd with copper (Cu) on the performance, selectivity, active site characteristics, and deactivation of a γ-Al2O3 supported Pd catalyst in MRCD of lignin using a CFR. Despite containing 49 % less Pd, the PdCu catalyst achieves the same depolymerization degree as the Pd catalyst over 200 min of time on stream. During the reaction, metallic Pd is formed within the Pd catalyst and both a smaller (unordered) and larger (ordered FCC) metallic PdCu phase within the PdCu catalyst. The enhanced performance of the PdCu catalyst is attributed to synergistic effects between Pd and Cu and presence of differently sized metallic phases. A minimal impact of Cu on the selectivity, even in monomer yields, was observed. For both catalysts, the primary cause of deactivation is the hydration of the γ-Al2O3 support to boehmite, leading to loss of its acidity and morphological changes. Metal leaching and poisoning are insignificant, while nanoparticle growth likely arises from the reduction of the metallic phases during reaction. Only a very small amount of coke deposition is observed. Overall, the cost-effective partial replacement of Pd with of Cu forms metallic PdCu alloys during the reaction, enhancing activity without adversely affecting selectivity or deactivation.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bimetallic nanoparticle catalysts, Bio-aromatics, Catalyst deactivation, Continuous flow reactor, Depolymerization, Heterogeneous catalysis, Lignin
in
Chemical Engineering Journal Advances
volume
22
article number
100710
pages
7 pages
publisher
Elsevier
external identifiers
  • scopus:85216591428
ISSN
2666-8211
DOI
10.1016/j.ceja.2025.100710
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2025 The Author(s)
id
9a44d567-0e7e-4da5-b03e-87e00cad85a4
date added to LUP
2025-02-26 14:38:30
date last changed
2025-04-04 14:38:33
@article{9a44d567-0e7e-4da5-b03e-87e00cad85a4,
  abstract     = {{<p>Mild reductive catalytic depolymerization (MRCD) of lignin offers a sustainable route to produce functionalized aromatic compounds. However, the economic viability is hindered by the need for expensive palladium (Pd) catalysts and the limited exploration of continuous flow reactors (CFRs), which are essential to achieve an adequate production scale. This study examines the impact of partial replacement of Pd with copper (Cu) on the performance, selectivity, active site characteristics, and deactivation of a γ-Al<sub>2</sub>O<sub>3</sub> supported Pd catalyst in MRCD of lignin using a CFR. Despite containing 49 % less Pd, the PdCu catalyst achieves the same depolymerization degree as the Pd catalyst over 200 min of time on stream. During the reaction, metallic Pd is formed within the Pd catalyst and both a smaller (unordered) and larger (ordered FCC) metallic PdCu phase within the PdCu catalyst. The enhanced performance of the PdCu catalyst is attributed to synergistic effects between Pd and Cu and presence of differently sized metallic phases. A minimal impact of Cu on the selectivity, even in monomer yields, was observed. For both catalysts, the primary cause of deactivation is the hydration of the γ-Al<sub>2</sub>O<sub>3</sub> support to boehmite, leading to loss of its acidity and morphological changes. Metal leaching and poisoning are insignificant, while nanoparticle growth likely arises from the reduction of the metallic phases during reaction. Only a very small amount of coke deposition is observed. Overall, the cost-effective partial replacement of Pd with of Cu forms metallic PdCu alloys during the reaction, enhancing activity without adversely affecting selectivity or deactivation.</p>}},
  author       = {{De Saegher, Tibo and Elmroth Nordlander, Jonas and Hallböök, Filip and Atanasova, Boyana and Vermeir, Pieter and Van Geem, Kevin M. and De Clercq, Jeriffa and Verberckmoes, An and Hulteberg, Christian and Lauwaert, Jeroen}},
  issn         = {{2666-8211}},
  keywords     = {{Bimetallic nanoparticle catalysts; Bio-aromatics; Catalyst deactivation; Continuous flow reactor; Depolymerization; Heterogeneous catalysis; Lignin}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Chemical Engineering Journal Advances}},
  title        = {{Mild reductive catalytic depolymerization of lignin in a continuous flow reactor using a Cu-enhanced Pd catalyst}},
  url          = {{http://dx.doi.org/10.1016/j.ceja.2025.100710}},
  doi          = {{10.1016/j.ceja.2025.100710}},
  volume       = {{22}},
  year         = {{2025}},
}