Acquiring an Efficient Warm‐CO₂ Sorbent from Advanced Pyrolysis of Magnesium Oxalate

Abstract For the first time, porous MgO with a Brunauer–Emmett–Teller (BET) surface area over 200 m² g⁻¹ can be simply obtained from pyrolysis of common magnesium oxalate without any solvent or additive. The obtained porous MgO had a large surface area of 278.5 m² g⁻¹ and captured 30.8 mg g⁻¹ of CO₂ in the instantaneous adsorption at 473 K, comparable with many MgO‐based sorbents prepared through complex procedures. Use of a U‐pipe furnace along with the specific “throughout” sweeping mode of nitrogen carrier gas enable this efficient warm‐CO₂ sorbent to be fabricated in a simple way. Factors including contacting modes between precursor salt and flowing gas, flow rate, type of gas and salt were carefully studied, and related to the pore structure and adsorption character of the MgO samples. Apart from the capability of trapping CO₂ mixed with SO₂ and NO at 473 K, the MgO sample showed a high ratio of exposed strong basic sites (70.5 %), which provides a useful solid strong base for control of CO₂ in flue gas.