Influence of Oxidation on the Preparation of Porous Carbons from Phenol−Formaldehyde Resins with KOH Activation

Abstract

The influence of oxidation on the production of high-porosity carbons from phenol−formaldehyde resins with KOH activation were examined under various preparation conditions. The activation process principally consisted of KOH impregnation followed by carbonization. Experimental results showed that prior to carbonization treating the resins with oxygen at 120 °C, either before or after KOH impregnation, enabled the enhancement of the yield of the carbon products. The porosity development was found to be hindered by conducting oxidation prior to the impregnation. For oxidation performed after the impregnation, at a low KOH/resin ratio the porosity was found to decrease upon oxidation, whereas the oxidation enhanced porosity development for activation performed at higher ratios. Varying the carbonization temperature and time did not show obvious influence on the effects of the oxidation.

Electric double layer capacitors based on a composite electrode of activated mesophase pitch and carbon nanotubes

“…Pore development in the pitch-derived carbon is associated with the formation of potassium-graphite intercalation compounds and with the direct attack of molten KOH on the basal planes of the microcrystalline structure formed during heating. [32][33][34][35][36] In the former route, removal of the potassium metal by water or HCl solution from the potassium-graphite intercalation compounds creates slit-like micropores that contribute a great proportion of the specific surface area of the resulting carbon. 33 In the latter, molten KOH penetrates perpendicularly into the microcrystalline layers, creating wedge-like pores with a wide (mesoporous) entrance zone and a narrow (microporous) bottom.…”

A simplified preparation of mesoporous carbon and the examination of the carbon accessibility for electric double layer formation

“…doi:10.1016/j.carbon.2004. 10.020 have become increasingly important as precursors for porous carbons in the form of fibers or particles [36][37][38][39].…”

Development of Microporosity in Mesoporous Carbons

“…This method is not only the way to create new, fine pores but also to enlarge already existing ones [59][60][61][62]. It was shown elsewhere [63][64][65] that the KOH activated carbons prepared from phenolic resins exhibit large pore volumes and high BET surface areas. In this work, the monolithic carbons synthesized from different polymer blends were subjected to the KOH activation; the resulting micro-mesoporous carbons are denoted as MC-RC-KOH, MC-PP-KOH, and MC-RF-KOH.…”