Acta Phys. -Chim. Sin. ›› 2022, Vol. 38 ›› Issue (10): 2206019.doi: 10.3866/PKU.WHXB202206019

Special Issue: Catalytic Conversion of Biomass

• ARTICLE • Previous Articles     Next Articles

Selective Hydrogenation of 5-(Hydroxymethyl)furfural to 5-Methylfurfural by Exploiting the Synergy between Steric Hindrance and Hydrogen Spillover

Shaopeng Li1,2,3, Jing Du3, Bin Zhang1, Yanzhen Liu1, Qingqing Mei1, Qinglei Meng1,3, Minghua Dong1,2, Juan Du1, Zhijuan Zhao1, Lirong Zheng4, Buxing Han1,2,5, Meiting Zhao3,*(), Huizhen Liu1,2,5,*()   

  1. 1 Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid and Interface and Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
    2 School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
    3 Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China
    4 Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
    5 Physical Science Laboratory, Huairou National Comprehensive Science Center, Beijing 101407, China
  • Received:2022-06-14 Accepted:2022-07-21 Published:2022-07-29
  • Contact: Meiting Zhao,Huizhen Liu E-mail:mtzhao@tju.edu.cn;liuhz@iccas.ac.cn
  • About author:Huizhen Liu, E-mail: liuhz@iccas.ac.cn
    Meiting Zhao, E-mail: mtzhao@tju.edu.cn
  • Supported by:
    the National Key Research and Development Program of China(2017YFA0403003);the National Key Research and Development Program of China(2017YFA0403101);National Natural Science Foundation of China(21871277);National Natural Science Foundation of China(21603235);National Natural Science Foundation of China(21403248);National Natural Science Foundation of China(21905195);China Postdoctoral Science Foundation(2021M702435);Beijing Municipal Science & Technology Commission(Z191100007219009)

Abstract:

Selective hydrogenation is a vital class of reaction. Various unsaturated functional groups in organic compounds, such as aromatic rings, alkynyl (C≡C), carbonyl (C=O), nitro (-NO2), and alkenyl (C=C) groups, are typical targets in selective hydrogenation. Therefore, selectivity is a key indicator of the efficiency of a designed hydrogenation reaction. 5-(Hydroxymethyl)furfural (HMF) is an important platform compound in the context of biomass conversion, and recently, the hydrogenation of HMF to produce fuels and other valuable chemicals has received significant attention. Controlling the selectivity of HMF hydrogenation is paramount because of the different reducible functional groups (C=O, C-OH, and C=C) in HMF. Moreover, the exploration of new routes for hydrogenating HMF to valuable chemicals is becoming attractive. 5-Methylfurfural (MF) is also an important organic compound; thus, the selective hydrogenation of HMF to MF is an essential synthetic route. However, this reaction has challenging thermodynamic and kinetic aspects, making it difficult to realize. Herein, we propose a strategy to design a highly efficient catalytic system for selective hydrogenation by exploiting the synergy between steric hindrance and hydrogen spillover. The design and preparation of the Pt@PVP/Nb2O5 catalyst (PVP = polyvinyl pyrrolidone; Nb2O5 = niobium(V) oxide) were also conducted. Surprisingly, HMF could be converted to MF with 92% selectivity at 100% HMF conversion. The reaction pathway was revealed through the combination of control experiments and density functional theory calculations. Although PVP blocked HMF from accessing the surface of Pt, hydrogen (H2) could be activated on the surface of Pt due to its small molecular size, and the activated H2 could migrate to the surface of Nb2O5 through a phenomenon called H2 spillover. The Lewis acidic surface of Nb2O5 could not adsorb the C=O group but could adsorb and activate the C-OH group of HMF; therefore, when HMF was adsorbed on Nb2O5, the C-OH groups were hydrogenated by the spilled over H2 to form MF. The high selectivity of this reaction was realized because of the unique combination of steric effects, hydrogen spillover, and tuning of the electronic states of the Pt and Nb2O5 surfaces. This new route for producing MF has great potential for practical application owing to its discovered advantages. We believe that this novel strategy can be used to design catalysts for other selective hydrogenation reactions. Furthermore, this study demonstrates a significant breakthrough in selective hydrogenation, which will be of interest to researchers working on the utilization of biomass, organic synthesis, catalysis, and other related fields.

Key words: Biomass, 5-Hydroxymethylfurfural, Selective hydrodeoxygenation, Steric hindrance, Hydrogen spillover