Enhancing the room-temperature catalytic degradation of formaldehyde through constructing surface lewis pairs on carbon-based catalyst

In this study, we construct the surface Lewis pairs, involving electron-rich nitrogen (Lewis base) sites and electron-deficient carbon (Lewis acid) sites, on carbon-based catalysts to enhance the catalytic activity towards the room-temperature decomposition of formaldehyde (HCHO). Density functional theory (DFT) calculation results show that the Lewis pairs, especially pyrrolic nitrogen species, contributed to the efficient HCHO adsorption ability. After the adsorbed HCHO molecules are oxidized into CO2 and H2O, and the Lewis acid-base catalytic sites finally get re-exposed, further initiating the next round of HCHO adsorption-decomposition process. Experimental measurements found that the typical sample exhibits an excellent catalytic HCHO oxidation activity, with the maximum HCHO removal efficiency of about 98.0 %, and the catalytic activity remains relatively unchanged after five cycles of reuse. This study may also open a new strategy to construct novel Lewis pairs for the removal of HCHO from other heteroatom-doped (e.g., B, S, F) porous carbon-based materials.