4 years ago

Importance of Angelica Lactone Formation in the Hydrodeoxygenation of Levulinic Acid to γ-Valerolactone over a Ru(0001) Model Surface

Importance of Angelica Lactone Formation in the Hydrodeoxygenation of Levulinic Acid to γ-Valerolactone over a Ru(0001) Model Surface
Andreas Heyden, Jesse Q. Bond, Mohammad Saleheen, Osman Mamun
Using mean-field microkinetic modeling with parameters derived from density functional theory calculations and harmonic transition state theory, we investigated the steady-state catalytic hydrodeoxygenation of levulinic acid (LA) to γ-valerolactone (GVL) on a Ru(0001) model surface. Focusing on the importance of intramolecular esterification of LA to its stable derivative α-angelica lactone (AGL) during the HDO to GVL, we studied various reaction pathways for GVL production that involve AGL and 4-hydroxypentanoic acid (HPA). We find that in a nonpolar reaction environment these pathways are not kinetically relevant but that GVL can be produced from LA by a single hydrogenation step, followed by ring closure and C–OH bond cleavage. However, AGL reaction pathways lead to surface poisoning at temperatures above 423 K when these pathways become kinetically accessible. As a result of surface poisoning—possibly at low temperatures by hydrogen and at high temperatures by AGL derivatives—we observe two different activity regimes characterized by significantly different activation barriers. Overall, simulation results agree well with experimental observations except at low temperatures of 323 K where our model significantly underestimates the turnover frequency, questioning whether Ru(0001) sites are active at these low temperatures.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b06369

DOI: 10.1021/acs.jpcc.7b06369

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.