Catalytic ability of MgO to break CH bonds during slurry oil carbon deposition

Abstract Although MgO has been widely used for the MgO-templated synthesis of carbon materials, little attention has been paid to MgO’s catalytic function during carbon deposition. Here, a systematic analysis of the products of slurry oil (SO) carbonization with and without MgO templates present indicates that MgO catalytically promoted the breakage of C H bonds by immobilizing heavy oil molecules on MgO surfaces and the attractive interaction between hydrogen and MgO. Compared with the carbonization of SO alone, a notably higher H 2 concentration and a lower hydrocarbon concentration was observed in the tail gas, a higher solid yield and a lower degree of graphitization of the carbon product were observed when MgO was also present. Furthermore, treatment at 900 °C in the presence of MgO efficiently enhanced the capacitance and rate capability of the as-obtained porous carbon when tested as an electrode material for supercapacitors. These results suggest that the catalytic function of MgO could exist in all MgO-templated syntheses and in the heat treatment of porous carbons and graphene.