Selective 5-Hydroxymethylfurfural Hydrogenolysis to 2,5-Dimethylfuran over Bimetallic Pt-FeOx/AC Catalysts

Yongjie Xin,Lungang Chen,Qiying Liu,Shuang Li,Sichan Li,Haiyong Wang

doi:10.3390/catal11080915

Abstract

The selective hydrogenolysis of 5-hydroxymethylfurfural (HMF) platform molecule to 2,5-dimethylfuran (DMF) has attracted increasing attention due to its broad range of applications. However, HMF, with multiple functional groups, produces various byproducts, hindering its use on an industrial scale. Herein, a bimetallic Pt-FeOx/AC catalyst with low Pt and FeOx loadings for selective HMF hydrogenolysis to DMF was prepared by incipient wetness impregnation. The structures and properties of different catalysts were characterized by XRD, XPS, TEM, ICP-OES and Py-FTIR techniques. The addition of FeOx enhanced Pt dispersion and the Lewis acidic site density of the catalysts, and was found to be able to inhibit C=C hydrogenation, thereby im-proving DMF yield. Moreover, the presence of Pt promoted the reduction of iron oxide, creating a strong interaction between Pt and FeOx. This synergistic effect originated from the activation of the C–O bond over FeOx species followed by hydrogenolysis over the adjacent Pt, and played a critical role in hydrogenolysis of HMF to DMF, achieving a yield of 91% under optimal reaction conditions. However, the leaching of Fe species caused a metal–acid imbalance, which led to an increase in ring hydrogenation products.

Highlights

With the development of technology, the continued exploitation of fossil fuels is causing more and more environmental problems, such as global warming owing to massive greenhouse gas emissions [1,2,3,4]
Following a comparison with the literature, it was observed that the formation rate of DMF over a 0.5% Pt-2% FeOx/AC catalyst was relatively high, and that the low loading of Pt presented an advantage considering the DMF yield and average reaction rate (Table S2)
The number of Brønsted and Lewis acidic sites in the sample was analyzed by calculating the peak areas based on the absorption peaks at around ~1545 cm−1 and ~1450 cm−1, respectively

Summary

Introduction

With the development of technology, the continued exploitation of fossil fuels is causing more and more environmental problems, such as global warming owing to massive greenhouse gas emissions [1,2,3,4]. Luo and coworkers prepared Pt-Ni, Pt-Zn and Pt-Cu alloyed catalysts using carbon as a support for HMF hydrogenolysis, and achieved DMF yields of 98%, 97% and 96%, respectively, at a pressure of 3.3 MPa H2 and between 160 and 200 ◦C [21]. Bimetallic catalysts such as Ru-Co/SiO2 [22], PtCo@HCS [23] and Cu−Pd@C [6] etc. A plausible reaction pathway and synergistic effect between metallic Pt and acidic FeOx are proposed in this paper

Catalyst Characterization

Catalytic Performance

Catalyst Stability

Conclusions