Recognizing the potential of K-salts, apart from KOH, for generating porous carbons using chemical activation

[Display omitted] •Chemical activation using potassium (K) salts excluding potassium hydroxide (KOH).•Mechanism details of K-salts to produce highly developed porous carbons.•Textural properties, morphology, elemental composition, and yield of porous carbons.•Potential of porous carbons for gas capture, energy storage, and contaminants removal. Due to their high porosity, chemically activated porous carbons find extensive use in various applications including gas capture, energy storage, and environmental remediation. Such porous carbons are predominantly produced using KOH as a chemical activating agent, which is highly corrosive, toxic, and harmful to the environment. As an alternative, several other potassium-based salts including K2CO3, KHCO3, K3C6H5O7, KC2H3O2, K2C2O4, K2FeO4, and K2SO4 can also produce high porosity in the porous carbons via chemical activation with negligible detrimental effects on the environment. This review, which is the first of its kind, discusses the usefulness of various K-salts, other than KOH, in producing porous carbons with competitive results in terms of various physico-chemical features and their impact on various application fields. This review also discusses the methodology and mechanistic aspects of various K-salts for chemical activation. Up-to-date literature is reviewed for the above-mentioned purposes that would provide the readers with useful information on the evolution of various K-salts, other than KOH, for their usefulness and future potential in chemical activation to produce highly efficient porous carbons for various applications.