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

Abstract

The advancement of cost-effective Pt catalysts for volatile organic compound (VOC) combustion holds significant importance. Enhancing the adsorption and activation of O 2 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 Fe 2 O 3 sample (Pt q / Sn q :Fe 2 O 3 ). 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 Pt q / Sn q :Fe 2 O 3 . Also, the Sn doping would enhance the interaction between the Fe 2 O 3 support and Pt to modulate the Pt's electronic structure, promoting the adsorption of toluene and the desorption of product CO. Thus, the developed Pt q /Sn q :Fe 2 O 3 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 Pt q /Sn q :Fe 2 O 3 . This research could offer a potential avenue for fine-tuning the structure of active sites crucial for catalytic processes.