Unveiling the impurity phase self-promoting mechanism in minerals-derived Li4SiO4 for enhanced CO2 capture performance

Although minerals-derived Li 4 SiO 4 demonstrates enhanced CO 2 capture performance and cost-effectiveness, the specific impurity-derived dopants governing cyclic stability and sorption kinetics still remain poorly understood. In this contribution, we reveal that Al doping (Si/Al = 3.76–5.68) improves cyclic stability by serving as both structural separator and support, while Na doping (Si/Na ≤20.6) enhances sorption capacity and kinetics. DFT simulations confirm Al reduces surface energy while Na increases exposure facet adsorption energy. Perlite is selected as the optimal silicon source from six minerals, and the derived perlite-Li 4 SiO 4 demonstrates superior CO 2 sorption capacities of 33.9 wt% at 650 °C and 8.3 wt% at 400 °C under 100 vol% CO 2 , maintaining 92% initial capacity even under low CO 2 concentrations (20%). Remarkable regeneration stability is observed through 100 cycles with only 1.7 wt% capacity loss. Lower activation energy (chemisorption phase) and 1.73 GJ/t CO 2 regeneration heat confirm its industrial viability. The impurity-doping synergism elucidates a self-reinforcing rationale for engineering stable high-temperature CO 2 capture materials with operational durability.