Modulating Lewis acid sites via P-doping to enable SO₂-tolerant catalytic oxidation

Area of Science:

• Catalysis
• Materials Science
• Environmental Chemistry

Background:

• Sulfur dioxide (SO2)-induced deactivation is a key challenge for transition metal oxide (TMO) catalysts.
• Developing SO2-tolerant catalysts is crucial for industrial applications.

Purpose of the Study:

• To design and synthesize P-doped MnO2 catalysts for SO2-tolerant toluene oxidation.
• To investigate the mechanism behind the enhanced SO2 tolerance and catalytic activity.

Main Methods:

• Synthesis of P-doped MnO2 catalysts.
• Characterization of catalyst properties (e.g., Lewis acid sites, oxygen vacancies).
• Evaluation of catalytic performance in toluene oxidation under SO2 exposure.

Main Results:

• P-doping significantly enhances Lewis acid site strength and accessibility in MnO2.
• Increased surface oxygen vacancies and lattice oxygen activation were observed.
• The P-doped MnO2 catalyst exhibited robust durability and high performance in SO2-containing environments, comparable to noble metal catalysts.
• Weakened SO2 chemisorption and suppressed Mn sulfation were key factors for durability.

Conclusions:

• Modulating surface acid sites through P-doping is an effective strategy for designing SO2-tolerant TMO catalysts.
• The synergistic effect of enhanced Lewis acid sites and surface oxygen vacancies drives superior catalytic activity and stability.
• This research offers a new pathway for developing durable catalysts for oxidation reactions in the presence of SO2.