Activation of Pt Nanoclusters on TiO2 via Tuning the Metallic Sites to Promote Low-Temperature CO Oxidation

Metallic Pt sites are imperative in the CO oxidation reaction. Herein, we demonstrate the tuning of Pt sites by treating a Pt catalyst in various reductive atmospheres, influencing the catalyst activities in low-temperature CO oxidation. The H-2 pretreatment of Pt clusters at 200 & DEG;C decreases the T-50 from 208 & DEG;C to 183 & DEG;C in the 0.1 wt % Pt/TiO2 catalyst. The T-50 shows a remarkable improvement using a CO pretreatment, which decreases the T-50 further to 135 & DEG;C. A comprehensive characterization study reveals the integrated reasons behind this phenomenon: (i) the extent of PtO transition to metallic Pt sites, (ii) the ample surface active oxygen triggered by metallic Pt, (iii) the CO selectively adsorbs on metallic Pt sites which participate in low-temperature CO oxidation, and (iv) the formation of the unstable intermediate such as bicarbonate, contributes together to the enhanced activity of CO pretreated Pt/TiO2.

Automated summary

Metallic Pt sites are crucial in CO oxidation reaction. Treating Pt catalyst in various reductive atmospheres can tune Pt sites and influence catalyst activities, with CO pretreatment showing significant improvement in low-temperature CO oxidation.