Carbocatalysis is a form of catalysis that uses heterogeneous carbon materials for the transformation or synthesis of organic or inorganic substrates. The catalysts are characterized by their high surface areas, surface functionality, and large, aromatic basal planes.

Carbocatalysis can be distinguishable from supported catalysis (such as palladium on carbon) in that no metal is present, or if metals are present they are not the active species. As of 2010, the mechanisms of reactivity are not well understood."

Source; Wikipedia

However, intense research (including the actions of Graphene as a catalyst) is currently underway in order to :

[…] understand the reaction mechanism and the reasons for the remarkable catalytic activity."

Source : Chem. Rev. 2014, 114, 12, 6179–6212