Platinized titanium dioxide (Pt/TiO₂) as a multi-functional catalyst for thermocatalysis, photocatalysis, and photothermal catalysis for removing air pollutants

Catalytic approaches are regarded as a highly favorable option to treat carcinogenic volatile organic compounds (VOCs: e.g., formaldehyde) released from various sources in indoor and outdoor environment. Among a wide range of engineered materials (e.g., metal oxide-supported noble metals), platinized titanium dioxide (Pt/TiO₂) is recognized as a highly effective multi-functional catalyst (e.g., thermocatalyst, photocatalyst, and photothermal-catalyst (as a synergistic combination of the former two)). In this review, an in-depth discussion is offered to describe the applicability of this multi-functional platform towards the removal of gaseous pollutants in light of its numerous advantages (e.g., high removal efficiency, stability, regenerability, and sustainability). Further, the discussion is expanded to address the effects of diverse variables on its performance including inherent material characteristics (e.g., surface chemistry, structure, morphology, and functionalities), process variables (e.g., relative humidity, temperature, and reactant composition), and the underlying mechanisms. To this end, quantitative criteria are established to pursue an evaluation of its performance in a less biased manner for each of all different types of catalytic functions. Finally, the current knowledge gaps and suitable research avenues are discussed for an in-depth exploration of this unique catalytic system.