Regulation of Ni valence state and synergistic effects of supports in the hydrodeoxygenation of lignin-derived vanillin using pseudoboehmite-supported Ni catalysts

ABSTRACT

Preparing 2-methoxy-4-methylphenol (MMP) through the vanillin (VAN) route is a crucial step in the high-value utilization of lignin (VTM). In this study, a series of Ni/PB catalysts were synthesized using pseudoboehmite (PB) as a carrier. Changes in the valence states of Ni were induced through H₂ activation, while the impacts of reaction temperature, initial pressure, and catalyst addition were investigated based on the VTM process. The results revealed that PB exhibited a distinct mesoporous structure (average pore size of 5.8 nm), with Ni loaded in small particles size (3.88 nm). Ni species on the catalyst existed in a + 2-valence state, undergoing a change after H₂ activation, with an increase in Ni⁰ promoting enhanced activity. The Ni/PB-450 catalyst exhibited excellent activity at 250°C for 3 hours (VAN conversion and MMP selectivity > 99%), and the catalyst demonstrated good durability, maintaining 99.1% VAN conversion and 80% MMP selectivity after two cycles. Combining the characterization and experimental results, the etherification and hydrogenation of VAN were identified as the primary reaction pathways. This study aimed to provide a new avenue for the high-value utilization of lignin and its derivatives through controlled catalyst preparation.

GRAPHICAL ABSTRACT

KEYWORDS:

• Vanillin
• Ni/PB
• 2-methoxy-4-methylphenol
• selective hydrodeoxygenation
• ethanol

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15567036.2024.2307374.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [No. 52206264, 51976112], the Program for Taishan Scholars of Shandong Province Government [No. tsqn202103066], the China Postdoctoral Science Foundation [No. 2021M691969], Youth Innovation Support Program of Shandong Colleges and Universities [2023KJ333], the visiting training funds for teachers from ordinary undergraduate colleges and universities in Shandong Province and the Natural Science Foundation of Shandong Province [No. ZR2022ME109, ZR2020ME185].

Notes on contributors

Rundong Liu

Rundong Liu is a master’s student at Shandong University of Technology, China. He mainly focuses on research on the high-value utilization of biomass.

Zhiyu Li

Zhiyu Li is an associate professor at Shandong University of Technology, China. He mainly engages in research on thermochemical conversion of biomass and utilization of solid waste resources.

Yuchun Zhang

Yuchun Zhang is an associate professor at Shandong University of Technology, China. Her main research interests are catalytic upgrading of biomass, CFD, multi-phase flow, biomass energy for hydrogen production.

Jinliang Yan

Jinliang Yan is a master’s student at Shandong University of Technology, China. He mainly focuses on research on the high-value utilization of biomass.

Wenwen Wang

Wenwen Wang is a master’s student at Shandong University of Technology, China. She mainly focuses on research on the high-value utilization of biomass.

Yangyang Lu

Yangyang Lu is a master’s student at Shandong University of Technology, China. He mainly focuses on research on the high-value utilization of biomass.

Peng Fu

Peng Fu is a professor in Shandong University of Technology, China. He has published more than 50 research articles in international journals. His research interests are thermal conversion of biomass to produce oil and gas fuels, heat transfer, renewable energy.