Catalysts are essential in industrial, chemical, and environmental applications, enabling efficient, selective, and sustainable chemical transformations. While conventional and nanostructured catalysts have significantly improved reaction rates and product yields, their use raises environmental concerns due to the presence of heavy metals and engineered nanoparticles, which can persist in soil and water, bio accumulate, and disrupt ecosystems. Improper disposal, limited recycling infrastructure, and insufficient regulatory frameworks exacerbate these risks. This review critically examines the environmental hazards of catalysts across their life cycle, including leaching, bioaccumulation, Eco toxicity, and airborne particulate release. It also highlights emerging low-impact strategies, such as TiO2-alternative photo catalysts, biocatalysts, and earth-abundant metal-based systems, reporting representative performance metrics like reaction efficiency, selectivity, and recyclability. By integrating life cycle assessment, eco-design principles, and circular economy approaches, these strategies demonstrate potential for reducing environmental footprint while maintaining high catalytic performance. The article provides insights for researchers, industry, and policymakers aiming to develop sustainable, low-risk catalytic technologies, bridging catalysis science with environmental management and regulatory frameworks. Highlights · Evaluates environmental risks of conventional and nanostructured catalysts. · Highlights pathways of catalyst-derived contamination in soil and water systems. · Reviews current challenges in catalyst disposal, recycling, and regulation. · Discusses green and bio-based catalysts as sustainable alternatives. · Proposes strategies for circular economy and eco-friendly catalyst design.
Nastaran Parsafard (Sun,) studied this question.