Improved one-pot synthesis of furfural from corn stalk with heterogeneous catalysis using corn stalk as biobased carrier in deep eutectic solvent-water system

Abstract

Using acid-treated corn stalk (CS) as biobased carrier, heterogeous SO₄^2-/SnO₂-CS catalyst was firstly prepared to catalyze CS into fufural in deep eutectic solvent-water system. The physical properties of SO₄^2-/SnO₂-CS were captured by FT-IR, NH₃-TPD, XRD, XPS, and BET. SO₄^2-/SnO₂-CS (1.2 wt%) could be used to catalyze CS (75.0 g/L) with MgCl₂ (15.0 g/L) to produce furfural (102.3 mM) in the yield of 68.2% for 0.5 h at 170 °C in ChCl:EG-water (20:80, v:v). Moreover, enhanced synthesis of furfural was explored based on the structure changes of CS, furfural yields and formation of byproducts. Finally, the potential catalytic mechanism for catalyzing CS into furfural and byproducts was proposed using SO₄^2-/SnO₂-CS as catalyst in ChCl:EG-water containing MgCl₂. In summary, this established ChCl:EG-water system and optimized catalytic condition facillitated to synthesize furfural from biomass with biobased solid acid catalyst.

Keywords: Corn stalks; Deep eutectic solvent; Furfural; MgCl(2); SO(4)(2−)/SnO(2)-CS.