Multistep Quenching of a Rust-Derived Catalyst for Enhanced Volatile Organic Compound Catalytic Oxidation

The advancement of cost-effective Pt catalysts for volatile organic compound (VOC) combustion holds significant importance. Enhancing the adsorption and activation of O2 and VOCs on catalysts is vital for VOC oxidation reaction. In this study, we utilized a two-step quenching method to alter iron rust, resulting in the deposition of Pt species on a Sn-doped Fe2O3 sample (Ptq/Snq:Fe2O3). Experiments and theoretical calculations revealed that both the two-step quenching process and the Sn dopants would induce the generation of oxygen vacancies, improving the adsorption and mobility of oxygen species on Ptq/Snq:Fe2O3. Also, the Sn doping would enhance the interaction between the Fe2O3 support and Pt to modulate the Pt's electronic structure, promoting the adsorption of toluene and the desorption of product CO. Thus, the developed Ptq/Snq:Fe2O3 exhibited boosted toluene/acetone oxidation activity, achieving 90% mineralization rate for toluene at 215 °C and acetone at 228 °C, respectively. In situ diffuse reflectance infrared Fourier transform spectroscopy showcased that the oxygen vacancy and Pt species with a modulated electronic structure synergistically heightened the activation of acetone/toluene, accelerated ring breakage of toluene, and brought about thorough oxidation of acetone on Ptq/Snq:Fe2O3. This research could offer a potential avenue for fine-tuning the structure of active sites crucial for catalytic processes.