Synthesis of tungsten iron-oxide zeolite composites and their catalytic degradation in VOC from rubber powder modified asphalt

Abstract

Tungsten iron-oxide zeolite composites with different Fe and W loadings were synthesized over NaY zeolite supports using a wet impregnation method. The composites exhibited suitable textural properties, light absorption, redox sites and acidity for photocatalytic VOC degradation. The photocatalytic activity for degrading acetaldehyde and o-xylene VOCs emitted from rubber powder modified asphalt was evaluated under solar irradiation. The 5Fe-10 W-NaY(2.8) composite achieved the highest VOC removal of 80% for acetaldehyde and 76% for o-xylene after 6 hours. Increasing Fe and W loading up to 5 wt% and 10 wt%, respectively, significantly enhanced the VOC degradation efficiency. Higher zeolite content and stronger acidity also boosted the photocatalytic performance. The degradation occurred via redox mechanisms involving photo-generated electrons, holes and reactive oxygen species, facilitated by the zeolite acid sites. The 5Fe-10 W-NaY(2.8) composite exhibited good stability over 5 reuse cycles, indicating its potential for mitigating VOC emissions from rubber powder modified asphalt pavements.

Keywords

• Zeolite
• Photocatalyst
• VOC degradation
• Asphalt
• Rubber powder