3 years ago

Size-dependent catalytic activity over carbon-supported palladium nanoparticles in dehydrogenation of formic acid

Size-dependent catalytic activity over carbon-supported palladium nanoparticles in dehydrogenation of formic acid
Hydrogen generation from formic acid (FA) under mild conditions has received significant attention, where Pd-based catalysts have been widely employed due to their superior activities. However, the Pd particle size effect has been much less systematically investigated. In this study, carbon-supported Pd nanoparticles (NPs) with five different Pd particle sizes, ranging from 2.1 to 4.5nm were synthesized using sodium citrate as the stabilizing agent. The Pd particle sizes were determined by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The FA dehydrogenation reaction was conducted in a FA-sodium formate (SF) aqueous solution in a batch reactor at room temperature. We found that decreasing the Pd particle size from 4.5±0.5 to 2.1±0.3nm remarkably boosted the catalytic activity by about 3.6 times, resulting in a turnover frequency of 835h−1, which is among the highest values for supported monometallic Pd catalysts in the literature. Our results suggest that both low- and high-coordination Pd surface atoms participated in the reaction. The remarkably higher activity of smaller Pd NPs was attributed to both higher Pd dispersion and the presence of a larger proportion of Pd species with positive charge, through which the Coulomb interaction between the positive Pd species and negative charged formate ions, the key reaction intermediate, is enhanced. Finally, the deactivation and regeneration of Pd/C catalysts were also discussed.

Publisher URL: www.sciencedirect.com/science

DOI: S0021951717302142

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.