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Both one‐pot catalytic conversion of furfural (FAL) to isopropyl levulinate (PL) and carbonization of by‐product (humins) for electromagnetic wave absorption are discussed, which provides inspiration that humins can be applied to electromagnetic wave absorption. In the former, phosphotungstic acid (PW) is employed as a homogeneous catalyst to convert FAL to PL via a tandem reaction in one pot, with the formation of a vast amount of humins. With FAL and various intermediates as substrates, it was found that humins was a polymerization product of FAL, furfuryl alcohol (FOL) and furfuryl ester (FE) with furan rings. In addition, the in situ attenuated total reflection infrared (ATR‐IR) spectra also provided a basis for the proposed reaction route. In the latter, with the humins as raw material, P species and WO3 doped nano‐porous carbon (Humins‐700) platform formed after high‐temperature annealing is used for electromagnetic wave absorption and manifests desirable absorption performance. The minimum reflection loss (RLmin) value is −47.3 dB at 13.0 GHz with a thickness of 2.0 mm and the effective absorption bandwidth reaches 4.5 GHz (11.2–5.7 GHz). [ABSTRACT FROM AUTHOR]

• Zirconium ion-intercalated montmorillonite was synthesized by a facile method. • The amount of Lewis and Bronsted acids could be altered by changing the concentration of zirconium ions. • One-pot cascade conversion of FAL to GVL was achieved under mild conditions. • Over 99% furfural conversion and 50.4% GVL yield were attained. A series of ultrathin metal intercalated montmorillonite (Mont) nanosheet materials were prepared and characterized for the one-pot cascade conversion of furfural (FAL) to obtain γ-valerolactone (γ-GVL). The coordination of the intercalated metal ions and the hydroxyl groups between the montmorillonite layers leads to an increase in the specific surface area and pore volume of the material, which coupled with the acidity of the metal ions themselves improves the catalytic performance of the material. Thus Zr-Mont-0.1 exhibited optimal catalytic performance with 100% conversion of FAL and 50.4% yield of GVL under mild conditions, and more importantly, the catalyst maintained its good catalytic performance after the fourth use. Meanwhile the number of Lewis and Brønsted acid sites in the Zr-Mont catalyst can be varied by adjusting the zirconium ion concentration. The proposed reaction mechanism provides initial insights into the role of metal-functionalized montmorillonite in catalyzing the reaction. In addition, the ten-fold magnification reaction confirmed the potential industrial application of the catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]