Development of glycerol-based metal-free carbon materials for environmental catalytic applications

•Metal-free carbon materials synthesized by partial carbonization and activation of glycerol.•High CWPO efficiency for heavily polluted aqueous solutions.•Oxidative thermal regeneration enables recovery of catalyst activity.

A thermally stable and non-porous carbon material (SBET = 10 m2 g−1 and no micropores), with low ash content and basic character, was produced by partial carbonization of glycerol with sulphuric acid followed by calcination under inert atmosphere. Further thermal activation in air atmosphere at different temperatures (from 150 to 350 °C) leads to materials with less basic character and to a tremendous evolution of the porosity, mostly microporosity (SBET = 598 m2 g−1 and VMic = 0.24 cm3 g−1). Experiments show that metal-free carbon materials synthesized by this approach can be highly active catalysts for the catalytic wet peroxide oxidation (CWPO) process when the surface chemistry and textural properties are adequately tuned. Effective catalytic degradation of 2-nitrophenol (80% conversion) was achieved with the material treated under air atmosphere at 300 °C, even when operating under a high pollutant/catalyst mass ratio, opening a window of opportunity for added-value crude glycerol-derived products. Furthermore, catalyst activity was effectively recovered by a simple oxidative thermal regeneration procedure.

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