Adsorption experiment
The purities of the acetylene, ethylene and carbon dioxide were higher than 99.99%. Their adsorption isotherms were collected with an Intelligent Gravimetric Analyser (IGA 001, Hiden, UK). Samples were activated under vacuum at 150 °C overnight or until no further weight loss was observed. Adsorption equilibrium data was collected once a stable pressure (more than 20 adsorption points were recorded from 0 to 1 bar) and weight was maintained for at least 40 min to reach an adsorption equilibrium at each point along the isotherm.