Moreover, the ions can react with coke that forms on catalyst surfaces to remove the coke (e.g., by processes such as sputtering, and/or via chemical reactions), either during cracking or catalyst regeneration.(ii) AlkylationIn petroleum terminology, alkylation refers to the reaction of low molecular weight olefins with an isoparaffin (e.g., isobutane) to form higher molecular weight isoparaffins.