Nitrogen-containing ordered mesoporous carbons applied as CO2 adsorbents and anode materials in energy storage devices

Porous carbons, thanks to their easily tunable features (porosity, surface chemical properties, etc.), can be employed for several applications: separation processes, as catalyst supports as well as electrode components in electrochemical energy storage/conversion devices. Among these, in the framework of strategies for the mitigation of global warming and climate changes, nitrogen-containing ordered mesoporous carbons (NOMCs) are proposed as CO2 adsorbents, thanks to their outstanding adsorption ability and selectivity. NOMCs can be synthesized with different pore architectures as nano-replications of a silica hard template, using a three-step procedure: i) infiltration of the carbon/nitrogen source inside the pore channels of silica, ii) pyrolysis of the hybrid system, and iii) template removal. This method is particularly useful for achieving the optimal textural properties, i.e. a hierarchical pore architecture composed of both micro- and mesopores able to promote at the same time improved capture performances and fast kinetics of gas diffusion, respectively. In this work, the aforementioned approach, known for the preparation of the so-called CMK-type materials, is exploited for tuning the textural features of the carbonaceous adsorbents. Moreover, a natural occurring nitrogen/carbon source was chosen as a precursor, in order to introduce basic sites useful to promote the interaction of the carbon framework with the acidic CO2 molecule, thus also fostering a selective adsorption in a gas mixture. Therefore, the regular, ordered mesoporous architecture and the chemical surface properties were investigated to unveil their effect on the CO2 capture performances. In addition, the described NOMCs can be applied not only for CO2 up-take, but also in energy storage and conversion devices (e.g., lithium or sodium-based batteries), photocatalysis or electrocatalytic reduction of CO2. For these applications, they can be used as-synthesized or eventually decorated with specifically selected metal oxides, and related results are here shown.