Frustrated Lewis pairs (FLP), a couple comprising a sterically encumbered Lewis acid and Lewis base, can offer latent reactivity for activating inert gas molecules. However, their use as a platform for fabricating gas‐responsive materials has not yet developed. Merging the FLP concept with polymers, we report a new generation CO2‐responsive system, differing from the first‐generation ones based on an acid–base equilibrium mechanism. Two complementary Lewis acidic and basic block copolymers, installing bulky borane‐ and phosphine‐containing blocks, were built as the macromolecular FLP. They can bind CO2 to drive micellar formation, in which CO2 as a cross‐linker bridges the block chains. This dative bonding endows the assembly with ultrafast response (<20 s), thermal reversibility, and excellent reproducibility. Moreover, such micelles bound highly active CO2 can function as nanocatalysts for recyclable C1 catalysis, opening a new direction of sustainable CO2 conversion.