Pelletized activated carbon-based CO-selective adsorbent with highly oxidation-stable and aggregation-resistant Cu(I) sites

Using Cu(I)-based adsorbent pellets with a high CO selectivity is crucial for efficient CO₂ conversion and H₂ production. However, their application is hindered by lack of pelletized adsorbents offering high performance and mechanical strength, severe degradation by Cu(I) oxidation under humid conditions, and activity loss due to Cu(I) aggregation at high-temperatures. Herein, these challenges were overcome by developing a Cu(I)-doped pelletized activated carbon (4.26Cu(I)@AC-600A) with highly aggregation-resistant Cu(I) sites that adsorbed 3.06 mmol CO g⁻¹ at 100 kPa (298 K). Its CO adsorption capacity remained 81% after a 12-week exposure to humid air, and was completely recovered by H₂ reduction at 473 K. Notably, 4.26Cu(I)@AC-600A had a high CO working capacity of 1.68 mmol g⁻¹ at the pressure swing of 10 to 100 kPa, showing no breakage when tested at 1000 kPa. Breakthrough experiments demonstrated the high performance of 4.26Cu(I)@AC-600A for efficient CO recovery or removal from various H₂ sources.