Plastic photoreforming: catalytic production of hydrogen and valuable chemicals

Abstract

The excessive emission of plastic pollutants has deteriorated the global environment dramatically, while conventional methods used to recycle plastics remain insufficient to mitigate these environmental impacts. In pursuit of highly efficient solutions, the plastic photoreforming technology is regarded as a green and sustainable approach, which not only enables the degradation of plastics but also concurrently produces hydrogen and high-value chemicals. As such, this review centralizes on summarizing the research progress of plastic photoreforming-based hydrogen production, covering plastic pretreatment, reaction mechanisms, photocatalyst design, and the produced chemicals. Unlike prior reviews, this review presents an innovative focus on chemical products such as formate and acetate generated during the photoreforming of plastics, underscoring this technology's dual-benefits in green energy recovery and generation of valuable feedstocks. Additionally, this review emphasizes the great potential of integrating photocatalysis with biology, materials science, and reaction engineering to develop bio-coupled photocatalytic systems for plastic photoreforming. Such coupled systems demonstrate synergistic contributions towards augmenting renewable energy output and accelerating pollutant degradation, thereby establishing an innovative framework to advance the development of sustainable technology. Furthermore, the prospects of sustainable development in this field are discussed, including material sustainability of photocatalysts, life-cycle assessment of photoreforming, and scalability and safety, which are crucial for ensuring the long-term viability, environmental impact reduction, and practical application of plastic photoreforming technology.