Sodium-lignosulfonate derived activated carbon: an investigation into the role of NaOH in the activation mechanism

We produced an activated carbon using sodium-lignosulfonate, in which we investigated how the sodium salt in lignin served as the activating agent during heat treatment. Our process resulted in a product with a high specific surface area of 1324 m 2 /g at 800 °C and microporous structure. During the activation process, we observed the consumption of carbon due to the dehydration reaction of NaOH and the reduction of Na 2 CO 3 to metallic Na, which created pores through oxidation/reduction reactions. The intercalation of metallic Na between the lattices at high temperatures formed additional pores and increased the specific surface area. Our proposed mechanism holds promise for enhancing the control of the microstructure and porosity of activated carbons through the thermal treatment of biomass. Graphical abstract