Adsorption of gaseous arsenic enhanced by lattice oxygen activation in pyrolusite: Method and mechanism

Atmospheric arsenic pollution from industrial flue gas emissions poses severe environmental and health risks, and necessitates the development of more efficient removal strategies. This study presents a novel approach for enhancing the As₂O₃(g) adsorption capacity of pyrolusite (PY) by activating its lattice oxygen to generate oxygen vacancies through ball milling. The activated PY can achieve an adsorption capacity of 13.84 mg/g at 300 °C, which is 1.6 times higher than that of pristine PY. Both experimental results and density functional theory calculations reveal the significance of oxygen vacancies, demonstrating increased electronic PY activity and improved lattice oxygen mobility. Furthermore, the lattice oxygen-mediated oxidation-adsorption pathway is elucidated, highlighting the pivotal role of oxygen vacancies in enhancing adsorption performance. This study provides an innovative pathway for designing highly efficient adsorbents for As₂O₃(g) removal, offering new insights into lattice oxygen activation mechanisms.