Bifunctional mechanism for low-temperature Methanol-SCR on H-FER zeolite doped by trace amount of cobalt

Green methanol is a promising alternative to fossil fuels in the fields where decarbonization is a major challenge, such as maritime transport. Selective catalytic reduction of NO_x by methanol (Methanol-SCR) offers a perfect deNO_x solution for methanol engines because of the co-existence of methanol and NO_x in the exhaust. Here, we developed Co-H-FER zeolites containing only trace amount of cobalt as low as 0.05 wt% as Methanol-SCR catalysts, giving rise to a surprised enhancement of deNO_x activity at low temperature region (250–350 °C) with excellent selectivity towards N₂. Atomically dispersed [Co-OH]^2 + species play a vital role in facilitating the generation of HONO species, which contribute to the formation of nitromethane as an initial step for the overall Methanol-SCR reaction. Bifunctional catalytic active sites including both [Co-OH]²⁺ sites and zeolite solid acid sites has been proposed for Methanol-SCR at low temperature.