| Abstract Scope |
High-temperature solid sorbents are essential for capturing CO2 emissions in energy-intensive industries, yet maintaining stability and adsorption capacity at high-temperatures remains a challenge. Herein, we report the fabrication of a novel oxidation-derived porous ceramic-foam engineered from a non-equimolar medium-entropy MAX phase, (Ti0.5V0.4Cr0.1)2AlC, as an efficient high-temperature CO2 sorbent. The ME-MAX phase was synthesized via a scalable, open-atmosphere molten-salt route. DFT calculations established its phase formability, whereas XRD, along with Rietveld refinement, confirms the feature of hexagonal ‘211’ MAX phase. SEM revealed the characteristic layered morphology; HR-TEM revealed the atomically resolved structure, while spatially resolved quantitative EELS determined the exact chemical composition of the ME-MAX particle. TG/DTA data demonstrated exceptional thermal stability upto 1400°C in an inert atmosphere and 650°C in air. A controlled, multistage-template sacrificial oxidation process was employed to transform the ME-MAX powder into an interconnected, open-cell foam, achieving a competitive CO2 uptake of 3.35 mmol/g at 500°C. |