Pyridinic-N induced reversible adsorption of high-boiling-point organic gases on functionalized mesoporous carbon

Abstract

Adsorptive capture of high-boiling-point organic gases (HBPOs) from hot flue gases is a key process in industry to tackle related environmental health or equipment clogging issues. However, few porous sorbents simultaneously achieve satisfactory adsorption capacity and regenerability due to strong affinity for HBPOs, compromising the economic viability and hindering the large-scale use of conventional disposable sorbents. In this work, we attempt to address this challenge by developing a functionalized mesoporous carbon (FMC) via the solution combustion synthesis method. Breakthrough experiments on phenanthrene and pyrene as representative HBPOs show that the FMC with lotus-shaped carbon sheet network, abundant 4–8 nm-concentrated mesoporosity, and oxygen/nitrogen-doped surface obtains unprecedented great capacity (1–2 orders of magnitude higher than reported values) and regenerability (peak desorption temperatures lower than respective boiling points). In situ characterizations and DFT simulations demonstrate the interfered π–π complexation as a highly reversible interaction between the carbonyl/pyridinic N-paired site and the polyaromatic adsorbate. The recyclability of FMC was demonstrated by negligible capacity reduction after 10 sorption cycles. This work showcases the potential for improving the economic feasibility of HBPOs capture by reducing the energy penalty and extending the sorbent lifetime.