CO-Assisted Methane Oxidation into Oxygenates over Surface Platinum-Titanium Alloyed Layers

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Methane oxidation with molecular oxygen is challenging due to spin state mismatches and difficulties in activating both methane and oxygen.
• Developing efficient catalysts for direct methane conversion into valuable oxygenates is crucial for sustainable chemistry.

Purpose of the Study:

• To develop a catalytic system for direct methane conversion into oxygenates using molecular oxygen.
• To investigate the role of platinum-titanium (Pt-Ti) alloyed layers on TiO2 in methane oxidation.

Main Methods:

• Synthesis of TiO2-supported Pt nanocrystals (Pt/TiO2) with surface Pt-Ti alloyed layers.
• Direct conversion of methane to oxygenates using O2 as the oxidant, with CO as a promoter, in an aqueous solution.
• Characterization using control experiments and spectroscopic techniques to identify active sites and reaction mechanisms.

Main Results:

• Achieved an oxygenate yield of 749.8 mmol gPt-1 with 62.3% methanol selectivity using 0.1% Pt/TiO2.
• Identified the surface Pt-Ti alloy as the active site for methane oxidation.
• Demonstrated that CO promotes O2 dissociation and subsequent methane activation on the Pt-Ti alloy surface.

Conclusions:

• Surface Pt-Ti alloyed layers on TiO2 are effective active sites for direct methane oxidation to oxygenates using O2.
• CO plays a crucial role in facilitating oxygen dissociation and methane activation, enabling efficient conversion.
• This study presents a promising catalytic approach for converting methane into valuable oxygenated products.