Pt supported on long-rod β-FeOOH as an efficient catalyst for HCHO oxidation at ambient temperature

Abstract

The physicochemical properties of surface hydroxyls have significant effects on the performance of HCHO oxidation catalysts. Herein, we report a method for modulating the properties of surface hydroxyls by changing the morphology of akaganéite (β-FeOOH) in Pt/FeOOH catalysts, and found that the Pt particles supported on long-rod β-FeOOH (Pt/FeOOH-LR) enclosed mainly by (010) and (001) planes exhibited better activity than those supported on short-rod or particle β-FeOOH (enclosed mainly by (001) and (100) planes). HCHO could be completely eliminated with an inlet concentration of 50 ppm at ambient temperature at a GHSV of 24 000 mL g⁻¹ h⁻¹ over Pt/FeOOH-LR. The use of long-rod β-FeOOH support improved the concentration of surface hydroxyls and enhanced the reducibility of Pt particles. The mechanism study by in situ DRIFTS and HCHO-TPSR indicated that the surface hydroxyls in Pt/FeOOH-LR could facilitate strong HCHO adsorption and are more active towards the surface formate oxidation. This strategy of modulating the properties of surface hydroxyls by shape engineering can be applied to develop novel catalysts for the hydroxyl-involved reactions.