Adjusting accommodation microenvironment for Cu + to enhance oxidation inhibition for thiophene capture

Cu + ‐containing materials have great potentials in various applications like adsorptive desulfurization. Nevertheless, their applications are severely obstructed by poor stability of Cu + in air. Here, we first clarify the mechanism of Cu + oxidation by first‐principle calculations and demonstrate that moisture accelerates Cu + oxidation dramatically. Then, the microenvironment of Cu 2 O‐modified HKUST‐1, a typical metal‐organic framework, is adjusted from hydrophilic to hydrophobic with polydimethylsiloxane coating (producing Cu 2 O@HK@P). This isolates moisture from pores and enhances the stability of Cu + significantly even under oxygen atmosphere. Cu + in Cu 2 O@HK@P preserves well after exposed to air for 6 months, while Cu 2 O@HK lose almost all Cu + for 2 weeks. The optimal Cu 2 O@HK@P can remove 540 μmol g −1 of thiophene from hydrous fuel, which is much superior to Cu 2 O@HK (227 μmol g −1 ) and most reported adsorbents. Our strategy can also be applied to stabilize Cu + in various materials including zeolite, mesoporous silica, and activated carbon.