Hydroxyl-Decorated Pt as a Robust Water-Resistant Catalyst for Catalytic Benzene Oxidation

In catalytic oxidation reactions, the presence of environmentalwater poses challenges to the performance of Pt catalysts. This studyaims to overcome this challenge by introducing hydroxyl groups ontothe surface of Pt catalysts using the pyrolysis reduction method.Two silica supports were employed to investigate the impact of hydroxylgroups: SiO2-OH with hydroxyl groups and SiO2-C without hydroxyl groups. Structural characterizationconfirmed the presence of Pt-O (x) , Pt-OH (x) , and Pt-0 speciesin the Pt/SiO2-OH catalysts, while only Pt-O (x) and Pt-0 species were observed inthe Pt/SiO2-C catalysts. Catalytic performance testsdemonstrated the remarkable capacity of the 0.5 wt % Pt/SiO2-OH catalyst, achieving complete conversion of benzene at160 & DEG;C under a high space velocity of 60,000 h(-1). Notably, the catalytic oxidation capacity of the Pt/SiO2-OH catalyst remained largely unaffected even in the presenceof 10 vol % water vapor. Moreover, the catalyst exhibited exceptionalrecyclability and stability, maintaining its performance over 16 repeatedcycles and a continuous operation time of 70 h. Theoretical calculationsrevealed that the construction of Pt-OH (x) sites on the catalyst surface was beneficial for modulatingthe d-band structure, which in turn enhanced the adsorption and activationof reactants. This finding highlights the efficacy of decorating thePt surface with hydroxyl groups as an effective strategy for improvingthe water resistance, catalytic activity, and long-term stabilityof Pt catalysts. Thedecoration of hydroxyl groups on Pt surfaces facilitatedelectron transfer from Pt to hydroxyl and adjusted the d-band structureof atomic Pt sites. This promotes the simultaneous activation of oxygenand adsorption of benzene, resulting in improving the water resistance,catalytic activity, and long-term stability of Pt/SiO2-OHcatalysts.

Automated summary

This study introduces hydroxyl groups onto the surface of Pt catalysts to overcome the challenges posed by environmental water in catalytic oxidation reactions. The presence of hydroxyl groups on the Pt catalysts enhances their catalytic activity and water resistance. Theoretical calculations reveal that the presence of hydroxyl groups modulates the d-band structure, improving the adsorption and activation of reactants.