Theoretical investigation of C1–C4 hydrocarbons adsorption and separation in a porous metallocavitand

Abstract

The purification of light hydrocarbons is one of the most important chemical processes globally which consumes substantial energy. Porous materials are likely to improve the efficiency of the separation process by acting as regenerable solid adsorbents. To investigate such translational systems, the underlying mechanism of adsorption in the porous materials must be taken into account. Herein we report the adsorption and selective separation of C1–C4 hydrocarbons in the coinage metal-based macrocyclic metallocavitand Pillarplex, which exhibits excellent performance in the adsorption of CH₄ at the ambient conditions with a binding energy of −17.9 kcal mol⁻¹. In addition, the endohedral adsorption of C2–C4 hydrocarbon is impressive. The CH₄, C₂H₄, C₃H₄, and 1,3-butadiene have potential uptake of 2.57, 4.26, 3.60, and 2.95 mmol g⁻¹, respectively at ambient conditions are highest from their respective isomers. Selective separation of C1–C4 hydrocarbons is studied using ideal adsorption solution theory demonstrating its potential for one-step purification of C1–C3 hydrocarbons.