Encapsulation of Carbon Nanotubes with Sulfonated Polymer for Photothermal Conversion of Fructose with Superior Productivity

Biomass valorization has been extensively explored to afford low-carbon fuels and chemicals, but it is generally impeded by high energy consumption and low efficiency. Here, we demonstrate that the impetus transition from bulk heating to photothermal effect for biomass valorization with excellent efficiency can be achieved via designing a composite (SPSS/DVB/CNT) of carbon nanotube and sulfonated polymer as a photothermal catalyst. The composite not only contained abundant acidic sites but also exhibited high light absorptivity and superior photothermal transformation ability. Under illumination, this catalyst could convert high-concentration fructose (31.3–47.6 wt %) to 5-hydroxymethylfurfural (HMF) with TOF up to 391.1 h–1 and reduced activation energy. With concentrated sunlight as the only energy input, this photothermal process delivered an HMF productivity of 8.9 mmol g–1 h–1 relative to the total weight of the catalytic system, which is considerably higher than the state-of-the-art catalytic systems. The superior performance is primarily attributed to the encapsulation structure that could induce a localized high-temperature gradient adjacent to the acidic sites to accelerate the desired reaction.