Two new basic ionic liquids (ILs) are designed and synthesized in order to conquer the challenge arising from the capture of CO2 in flue gas whose temperature is over 373 K, and they possess a suitable basic strength to adsorb CO2 at 393 K with the capacity of 22-49 mg g(-1). After these ILs are immobilized on mesoporous alumina or silica, equimolar CO2 capture is realized at 393 K for the first time. Besides, these adsorbents can be regenerated at 443 K to form a feasible cycle for controlling CO2 emission in flue gas. Theoretical calculations indicated the key role played by the mesoporous support in promoting CO2 adsorption via electrostatic interactions between support and ILs. An unwonted promotion of the support's ζ-potential on the performance of ILs is revealed, which induces the immobilized ILs to be oriented in a favorable dispersion, enhancing the efficiency of ILs in the CO2 adsorption at elevated temperature. This study proposes a new strategy for the sustainable development of novel adsorbent.