Mechanochemical Synthesis of Single Metal Atoms Loaded in Confined Ionic Liquids Composites for VOCs Remediation

Stabilisation and isolation of Single Atom Catalysts (SACs) remains a challenge due to the tendency of forming aggregation of metal nanoparticles or clusters. Supporting Ionic Liquids (ILs) in porous substrates (such as metal organic frameworks and zeolites) enhances physical sorption of Volatile Organic Compounds (VOCs) in a considerable manner, as ILs have excellent affinities and sorption capabilities towards organic molecules, whereas specific loadings of ILs optimize textural properties of the supporting substrates. Taking advantage of the ionic environment provided by ionic liquids, single metal atoms were successfully stabilized and prevented from aggregation within the structure of the IL/substrate composites. We report a simplified method to synthesise and prepare SACs loaded in ILs/porous substrates, by a mechanochemical approach based on ball milling technique. An evaluation of the stability of SACs within the ionic environment of different ionic liquids/substrates, as well as morphological changes derived from optimizing the working parameters of the milling technique is presented, together with an assessment of the sorption and catalytic performances towards selected VOCs of concern.