Innovations and future directions in hybrid non-thermal plasma-catalyst systems for VOC decomposition

Abstract

Volatile organic compounds (VOCs) are challenging to abate because conventional thermal and adsorption approaches trade high energy use for incomplete mineralization and by-product formation. Hybrid non-thermal plasma–catalyst (NTP–catalyst) systems address these limits by coupling plasma-generated oxidants with surfaces that steer reaction pathways at near-ambient bulk temperatures. This review examines NTP–catalyst performance across dielectric-barrier discharge, corona, and gliding-arc reactors, and across catalysts including oxygen-vacancy-rich MnO_x and CeO₂, TiO₂, zeolites, metal-organic frameworks (MOFs), and noble-metal dopants. We organize disparate results using five “matchings”: (i) position (in-plasma vs post-plasma placement), (ii) time-scale (microsecond plasma pulses vs millisecond–second surface kinetics), (iii) energy (specific input energy (SIE) optima beyond which carbon balance and CO₂ selectivity degrade), (iv) material (multi-metal sites and vacancy engineering), and (v) operation (temperature, humidity, and residence time). We synthesize trends on conversion, CO₂ selectivity, ozone slip, and partial-oxidation by-products, and discuss durability (coking, halogen/sulfur poisoning, plasma aging) alongside mitigation via robust supports, sacrificial oxygen, and periodic regeneration. Finally, we chart future directions: Nanosecond repetitively pulsed (NRP) and frequency-tunable power supplies; structured catalysts and reactors (honeycomb, packed/fluidized beds, and 3D-printed dielectrics) for uniform plasma–solid contact; multi-process hybrids (plasma + photocatalysis/ozonation) to lower energy intensity; in-situ/operando diagnostics and microkinetic–plasma modeling; and data-driven control (AI/ML) for real-time optimization and scale-up. This synthesis provides design guidance and research priorities toward industrially scalable, energy-efficient VOC abatement.