Water-assisted catalytic transfer hydrogenation of guaiacol to cyclohexanol over Ru/NiAl₂O₄

TY - JOUR

T1 - Water-assisted catalytic transfer hydrogenation of guaiacol to cyclohexanol over Ru/NiAl2O4

AU - Zhao, Yuying

AU - Zhan, Jiahui

AU - Hu, Rui

AU - Luo, Gang

AU - Fan, Jiajun

AU - Clark, James H.

AU - Zhang, Shicheng

N1 - Funding Information: This research was supported by the National Natural Science Foundation of China (No. 22278085 ). We thank the reviewers for their positive and constructive comments. Publisher Copyright: © 2024 Elsevier B.V.

PY - 2024/4/1

Y1 - 2024/4/1

N2 - Extensive use of grey hydrogen in traditional hydrodeoxygenation (HDO) severely reduces the sustainable development of lignin valorization processes. Conversely, the catalytic transfer hydrogenation (CTH) mediated by green hydrogen is an alternative strategy that promotes the sustainability of in-situ hydrogenation of lignin. In this work, a bifunctional catalyst (Ru/NiAl2O4) was developed to assist the proposed green hydrogen-driven cosolvent system composed of isopropanol and water for the CTH of guaiacol. Results indicate that 95% conversion of guaiacol and 80% cyclohexanol selectivity can be achieved at 200 ℃ within 3 h with a high water/isopropanol ratio (6/4), significantly increasing the greenness and sustainability. Furthermore, the recycling experiments verify the stability of the catalyst's active sites. Analysis of the mechanism suggests that the high efficiency of such system can be attributed to the activation of metal and acid dual functional sites of Ru/NiAl2O4 catalyst on aromatic rings and C-O bonds. The acceleration of the in-situ hydrogen supply is due to hydrogen exchange between water and isopropanol. The participation of water in the reaction is also demonstrated by the presence of deuterium in the product after the reaction in D2O. This work provided the insights into the development of a strategy for the production of cyclohexanol from lignin derivatives by an in-situ CTH system.

AB - Extensive use of grey hydrogen in traditional hydrodeoxygenation (HDO) severely reduces the sustainable development of lignin valorization processes. Conversely, the catalytic transfer hydrogenation (CTH) mediated by green hydrogen is an alternative strategy that promotes the sustainability of in-situ hydrogenation of lignin. In this work, a bifunctional catalyst (Ru/NiAl2O4) was developed to assist the proposed green hydrogen-driven cosolvent system composed of isopropanol and water for the CTH of guaiacol. Results indicate that 95% conversion of guaiacol and 80% cyclohexanol selectivity can be achieved at 200 ℃ within 3 h with a high water/isopropanol ratio (6/4), significantly increasing the greenness and sustainability. Furthermore, the recycling experiments verify the stability of the catalyst's active sites. Analysis of the mechanism suggests that the high efficiency of such system can be attributed to the activation of metal and acid dual functional sites of Ru/NiAl2O4 catalyst on aromatic rings and C-O bonds. The acceleration of the in-situ hydrogen supply is due to hydrogen exchange between water and isopropanol. The participation of water in the reaction is also demonstrated by the presence of deuterium in the product after the reaction in D2O. This work provided the insights into the development of a strategy for the production of cyclohexanol from lignin derivatives by an in-situ CTH system.

KW - Catalytic transfer hydrogenation

KW - Cyclohexanol

KW - Guaiacol

KW - Hydrogen exchange

KW - Water/isopropanol

UR - http://www.scopus.com/inward/record.url?scp=85186708126&partnerID=8YFLogxK

U2 - 10.1016/j.cej.2024.149934

DO - 10.1016/j.cej.2024.149934

M3 - Article

AN - SCOPUS:85186708126

SN - 1385-8947

VL - 485

JO - CHEMICAL ENGINEERING JOURNAL

JF - CHEMICAL ENGINEERING JOURNAL

M1 - 149934

ER -