High-Efficiency Production of Biomass-Derived 5-Alkoxymethylfurfurals over a Lewis–Brønsted Bifunctional Carbonaceous Acid Catalyst
Yetao Jiang, Jiacheng Li, Ling Zhang, Keru Chen, Na Shen, Minhui Yang, Xiaoyu Wang, Zhen Wu, Aiyong He, Jiaxing Xu, Lei Hu
Abstract
Biomass-derived 5-alkoxymethylfurfurals (AMFs) are an important kind of high-quality liquid biofuel or diesel additive, which are commonly produced by the etherification of 5-hydroxymethylfurfural (HMF) with alcohols. To produce various AMFs in a convenient and practical manner, the design of high-performance catalysts with preeminent catalytic universalities is a particularly interesting and meaningful task. Herein, we developed a useful carbonization–coordination–sulfonation strategy, which was employed to construct a Lewis–Brønsted bifunctional carbonaceous acid catalyst (Zr/GHTC–SO 3 H). The characterization results demonstrated that Zr/GHTC–SO 3 H contained strong Lewis acidic sites (Zr 4+ ) and Brønsted acidic sites (−SO 3 H), which could promote the etherification of HMF and then facilitate the formation of AMFs. Simultaneously, Lewis basic sites (O 2– ) in Zr/GHTC–SO 3 H were dramatically destroyed and weakened, which could restrict the transfer hydrogenation of HMF and then improve the selectivity of AMFs. Due to the synergistic effects of different active sites, Zr/GHTC–SO 3 H showed excellent catalytic performance and catalytic universality. When HMF was etherified in methanol, ethanol, n -propanol, isopropanol, n -butanol, and sec -butanol, the corresponding product yield could be up to 91.6, 94.8, 93.3, 94.4, 92.9, and 92.1% under the appropriate reaction conditions, respectively. Moreover, Zr/GHTC–SO 3 H was also a stable catalyst and displayed satisfactory reusability. In summary, this work presented a special research idea to prepare high-efficiency catalysts for the etherification of HMF to AMFs, which could also provide significant references for the production of other biomass-derived furanic ethers.