Abstract
Storing and in-situ hydrogenating CO2 to CH4 by dual functional materials (DFMs) is an efficient solution to alleviate the greenhouse effect and energy shortage. However, in the multi-step preparation process of DFMs, high-temperature calcination is usually required, solvent is used, and NO2/CO2 is inevitably emitted. In this work, we first reported that the Ni/MgO DFMs could be mechanochemically synthesized in one step at room temperature by magnesium-induced hydrogenation of Ni-mixed magnesium carbonate without using any solvent and NO2/CO2 emission. Integrated CO2 capture and methanation performance of the Ni/MgO DFMs are investigated isothermally in a TG-MS apparatus and a fixed bed reactor. The CO2 uptake and CH4 yield over the 80Ni/MgO DFM at 300 ℃ are 0.37 mmol/g and 0.27 mmol/g, respectively, with a CO2 conversion of 73.0 % and CH4 selectivity of 100 %. After 5 consecutive CO2 capture and methanation cycles at 300 ℃, the CO2 uptake and CH4 yield over the 50Ni/MgO DFM still are 0.26 mmol/g and 0.18 mmol/g, respectively, with a CO2 conversion of 69.2 % and CH4 selectivity of 100 %. Furthermore, the mechanism of CO2 adsorption, activation, and hydrogenation to methane over the Ni/MgO DFM is systematically investigated by using density functional theory (DFT) calculations. This study offers an alternative, green, and sustainable strategy to acquire DFMs for CO2 capture and methanation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have