Ultrasonic-assisted-microwave quick synthesis of Pd nanoparticles on N-doped porous carbon for efficient direct hydrogen peroxide synthesis from hydrogen and oxygen at atmospheric pressure

Abstract

Directly synthesizing H2O2 from H2 and O2 at atmospheric pressure requires a highly efficient Pd catalyst, which poses a challenge for reasonable design and simple synthesis of Pd catalyst. In this study, a series of Pd/NPCS catalysts were synthesized by various methods with mono-disperse, uniform-size and N-doped porous carbon sphere named NPCS as the support and PdCl2 as the palladium precursor. The results indicated that the ultrasonic-assisted-microwave quick synthesis method significantly reduced the synthesis time of Pd catalyst. The Pd nanoparticles obtained via this method were well-distributed on the NPCS support, with a smaller particle size, a narrower particle size distribution range, and more exposed Pd active sites, which leading to improved H2O2 generation rate compared to traditional preparation methods. Additionally, N-doped, high specific surface area, and abundant mixed micro-mesoporous pore structure of NPCS support improved the transfer and diffusion performance of Pd/NPCS catalysts, facilitating the adsorption of reactants and desorption of H2O2 from Pd active sites, and effectively inhibited hydrogenation and decomposition side reactions caused by the breaking of the O-O bond. The ultrasonic-assisted-microwave quick synthesis method and excellent NPCS support synergistically improved the catalytic activity and stability of Pd/NPCS catalyst. These findings provide insight into the design and preparation of efficient Pd catalysts for directly synthesizing H2O2 at atmospheric pressure.

Keywords

• Pd catalyst
• Ultrasonic-assisted-microwave
• Quick synthesis
• N-doped porous carbon
• The direct synthesis of H2O2 from H2 and O2