5 years ago

How Nitrogen-Doped Graphene Quantum Dots Catalyze Electroreduction of CO2 to Hydrocarbons and Oxygenates

How Nitrogen-Doped Graphene Quantum Dots Catalyze Electroreduction of CO2 to Hydrocarbons and Oxygenates
Jingjie Wu, Pulickel M. Ajayan, Boris I. Yakobson, Bilu Liu, Jia Li, Mingjie Liu, Xiaolong Zou
Recently, metal-free nitrogen-doped graphene quantum dots (NGQDs) have been experimentally demonstrated to electrochemically convert CO2 into high-order hydrocarbons and oxygenates, after more than 30 years since the identification of copper as an active metal catalyst for such conversions. However, the physicochemical principle of such catalytic activity for NGQDs has remained unclear. Here, by performing first-principles simulations, we have systematically investigated the underlying mechanisms governing the whole process. The introduction of N atoms into edges of graphene quantum dots enhances their bonding with *COOH, effectively promoting the reduction of CO2 to CO. By including the influences of water, we reveal that the selective production of CH4 over CH3OH is attributed to a much lower kinetic barrier for the conversion of adsorbed *CH2OH to *CH2 via water molecule mediated proton shuttling. Further, adsorbed *CH2 provides active sites for the coupling with CO to generate C2 products, including both C2H4 and C2H5OH. These results offer theoretical insights into the reduction pathways of CO2 on NGQDs, which may facilitate the design of metal-free carbon-based catalysts for efficient CO2 reduction.

Publisher URL: http://dx.doi.org/10.1021/acscatal.7b01839

DOI: 10.1021/acscatal.7b01839

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.