Mg-incorporated sorbent for efficient removal of trace CO from H<sub>2</sub> gas.

Bang, Gina; Jin, Seongmin; Kim, Hyokyung; Kim, Kyung-Min; Lee, Chang-Ha · Nat Commun · 2023

basic_science · Level V

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Abstract

Removal of trace CO impurities is an essential step in the utilization of Hydrogen as a clean energy source. While various solutions are currently employed to address this challenge, there is an urgent need to improve their efficiency. Here, we show that a bead-structured Mg, Cu, and Ce-based sorbent, Mg<sub>13</sub>CuCeO<sub>x</sub>, demonstrates superior removal capacity of trace CO from H<sub>2</sub> with high stability. The incorporation of Mg boosts sorption performance by enhancing the porous structure and Cu<sup>+</sup> surface area. Remarkably, compared to existing pelletized sorbents, Mg<sub>13</sub>CuCeO<sub>x</sub> exhibits 15.5 to 50 times greater equilibrium capacity under pressures below 10 Pa CO and 31 times longer breakthrough time in removing 50 ppm CO in H<sub>2</sub>. Energy-efficient oxidative regeneration using air at 120 °C allows its stable sorption performance over 20 cycles. Through in-situ DRIFTS analysis, we elucidate the reaction mechanism that Mg augments the surface OH groups, promoting the formation of bicarbonate and formate species. This study highlights the potential of MgCuCeO<sub>x</sub> sorbents in advancing the hydrogen economy by effectively removing trace CO from H<sub>2</sub>.