New review highlights advances in catalytic conversion of lignin into biofuels and chemicals

Lignin, a major component of plant biomass, is the only abundant natural source of renewable aromatic compounds. However, its complex structure makes it difficult to break down efficiently into useful products. A new review published in Energy & Environment Nexus explores recent advances in catalytic hydrodeoxygenation (HDO)—a key process for converting lignin-derived compounds into biofuels and high-value chemicals.

The review, led by researchers from Southeast University, discusses the reaction pathways, catalyst design, and performance of various heterogeneous catalysts, including metal sulfides, noble metals, and non-noble metal systems. The work provides a comprehensive guide for designing efficient and selective catalysts for HDO reactions under mild conditions.

“Lignin is a promising renewable feedstock for producing sustainable hydrocarbons, but its high oxygen content and complex structure pose significant challenges,” said corresponding author Prof. Huiyan Zhang. “Our review highlights how catalyst structure influences reaction pathways and product selectivity, offering strategies for better catalyst design.”

Key findings include:

• Metal sulfides like MoS₂, especially when doped with Co or Pt, show high activity and aromatic selectivity but require constant H₂S addition to maintain stability.

• Noble metal catalysts (Pt, Pd, Ru) exhibit excellent low-temperature activity but are expensive and prone to deactivation. Bimetallic and acid-functionalized catalysts can enhance stability and selectivity.

• Non-noble metal catalysts (Ni, Co, Fe) are cost-effective but often require structural modifications—such as phosphorus incorporation or alloying—to improve activity and suppress unwanted side reactions.

The authors also address challenges such as catalyst coking, water tolerance, and hydrogen consumption, and propose future directions for developing more economical, stable, and environmentally friendly HDO processes.

“Designing catalysts that operate efficiently at low temperatures and pressures is crucial for the economic viability of lignin valorization,” added Prof. Rui Xiao. “We hope this review will inspire further innovation in catalyst development and reaction engineering.”

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Journal reference:  Yu J, Gao Y, Zhang H, Xiao R. 2025. Hydrodeoxygenation of lignin derivatives on heterogeneous catalysts. Energy & Environment Nexus 1: e002 https://www.maxapress.com/article/doi/10.48130/een-0025-0008 

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About Energy & Environment Nexus:
Energy & Environment Nexus is an open-access journal publishing high-quality research on the interplay between energy systems and environmental sustainability, including renewable energy, carbon mitigation, and green technologies.

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