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

• Published in: Arabian journal of chemistry 2023-10, Vol.16 (10), p.105100, Article 105100
• Main Authors: Shi, Yongyong, Jiang, Donghai, Zhou, Liming, Zhao, Jingyun, Ma, Jun, Lin, Qian, Pan, Hongyan
• Format: Article
• Language: English
• Subjects: N-doped porous carbon; Pd catalyst; Quick synthesis; The direct synthesis of H2O2 from H2 and O2; Ultrasonic-assisted-microwave
• ISSN: 1878-5352; 1878-5379
• DOI: 10.1016/j.arabjc.2023.105100

A high performance Pd/NPCS catalyst used mono-disperse, uniform-size and N-doped porous carbon sphere named as NPCS as a support has been designed and synthesized by ultrasonic-assisted-microwave quick synthesis method for the direct synthesis of H2O2 from H2 and O2 at atmospheric pressure. [Display omitted] •A mono-disperse, size-uniform and nitrogen-doped porous carbon sphere (NPCS) with high specific surface area and hierarchical pore structure was prepared by a one-pot activation method.•The high-performance Pd/NPCS catalysts were rapidly synthesized using the ultrasonic-assisted-microwave quick synthesis method.•Adjusting the amount of H2PdCl4 allowed for the modulation of the surface Pd0/Pd2+ ratio of the Pd/NPCS catalysts. When the H2PdCl4 addition amount was 0.3 ml, the Pd0.3/NPCS catalyst exhibited a high hydrogen peroxide productivity of 219 molH2O2·kgcat-1·h−1. 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.