Selective suppression of key hazardous asphalt VOCs by MIL-101: From risk screening to mechanistic insights

Abstract

As a fundamental component of the global transportation network, asphalt pavements inevitably release complex volatile organic compounds (VOCs) throughout their entire life cycle, posing persistent threat to ecosystems and human health while hindering cleaner production in sector. Owing to the extreme compositional complexity of asphalt VOC emissions, existing studies have largely focused on total emission control, often overlooking the dominant contribution of a small number of highly toxic components to overall risk. To address this limitation, this study proposes a risk-oriented selective suppression strategy. A multidimensional evaluation framework was established to identify key hazardous components, prioritizing isoprene, p-xylene, dimethyl disulfide, and methyl vinyl ketone as primary control targets. Subsequently, a low-emission asphalt material was developed using the high-surface-area metal–organic framework MIL-101 as a modifier to enable targeted adsorption of these characteristic pollutants. Multiscale molecular simulations reveal that the abundant unsaturated metal sites and unique pore environment of MIL-101 generate deep free-energy wells and pronounced diffusion barriers, endowing the material with higher adsorption affinity and stronger intracrystalline retention for selective capture of the target pollutants. Gas chromatography–mass spectrometry (GC–MS) experiments further validate the simulation predictions, demonstrating that MIL-101 significantly reduces emissions of the risk-dominant pollutants, Overall, this work integrates risk-oriented screening with mechanism-guided material design, providing an effective pathway for cleaner production of low-emission asphalt materials and the development of more sustainable transportation infrastructure.