More Like this

1. Complex Structures Resulting from Carboxylic Acid Self-Assembly: Comparison of 2-Naphthoic Acid to Quinaldic Acid and 3-Quinoline Carboxylic Acid

   https://doi.org/10.1021/acs.jpcc.9b01817  

   Petersen, Jacob P. ; Brown, Ryan D. ; Silski, Angela M. ; Corcelli, Steven A. ; Kandel, S. Alex ( May 2019 , The Journal of Physical Chemistry C)
2. The driving effects of common atmospheric molecules for formation of clusters: the case of sulfuric acid, formic acid, hydrochloric acid, ammonia, and dimethylamine

   https://doi.org/10.1039/D3EA00087G  

   Longsworth, Olivia M. ; Bready, Conor J. ; Shields, George C. ( September 2023 , Environmental Science: Atmospheres)

   One of the main sources of uncertainty for understanding global warming is understanding the formation of larger secondary aerosols.

    

   more » « less
3. The driving effects of common atmospheric molecules for formation of clusters: the case of sulfuric acid, nitric acid, hydrochloric acid, ammonia, and dimethylamine

   https://doi.org/10.1039/D3EA00118K  

   Longsworth, Olivia M. ; Bready, Conor J. ; Joines, Macie S. ; Shields, George C. ( January 2023 , Environmental Science: Atmospheres)

   Secondary aerosols form from gas-phase molecules that create prenucleation complexes, which grow to form aerosols. Understanding how secondary aerosols form in the atmosphere is essential for a better understanding of global warming.

    

   more » « less
4. Vapor-phase conversion of aqueous 3-hydroxybutyric acid and crotonic acid to propylene over solid acid catalysts

   https://doi.org/10.1039/d1cy01152a  

   Leow, Shijie ; Koehler, Andrew J. ; Cronmiller, Lauren E. ; Huo, Xiangchen ; Lahti, Gabriella D. ; Li, Yalin ; Hafenstine, Glenn R. ; Vardon, Derek R. ; Strathmann, Timothy J. ( October 2021 , Catalysis Science & Technology)

   Diverse sources of wastewater organic carbon can be microbially funneled into biopolymers like polyhydroxybutyrate (PHB) that can be further valorized by conversion to hydrocarbon fuels and industrial chemicals. We report the vapor-phase dehydration and decarboxylation of PHB-derived monomer acids, 3-hydroxybutyric acid (3HB) and crotonic acid (CA), in water to propylene over solid acid catalysts using a packed-bed continuous-flow reactor. Propylene yields increase with increased Brønsted acidity of catalysts, with amorphous silica–alumina and niobium phosphate yielding 52 and 60 %C (percent feedstock carbon, max 75 %C) of feedstock 3HB and CA, respectively; additional products include CO 2 and retro-aldol products (acetaldehyde and acetic acid). Deactivation studies indicate progressive and permanent steam deactivation of amorphous silica–alumina, while re-calcination partially recovers niobium phosphate activity. Experiments demonstrating sustained reactor operation over niobium phosphate provide a promising technology pathway for increasing valorization of organic-rich wastewater. 

   more » « less
5. The driving effects of common atmospheric molecules for formation of prenucleation clusters: the case of sulfuric acid, formic acid, nitric acid, ammonia, and dimethyl amine

   https://doi.org/10.1039/D2EA00087C  

   Bready, Conor J. ; Fowler, Vance R. ; Juechter, Leah A. ; Kurfman, Luke A. ; Mazaleski, Grace E. ; Shields, George C. ( October 2022 , Environmental Science: Atmospheres)

   How secondary aerosols form is critical as aerosols' impact on Earth's climate is one of the main sources of uncertainty for understanding global warming. The beginning stages for formation of prenucleation complexes, that lead to larger aerosols, are difficult to decipher experimentally. We present a computational chemistry study of the interactions between three different acid molecules and two different bases. By combining a comprehensive search routine covering many thousands of configurations at the semiempirical level with high level quantum chemical calculations of approximately 1000 clusters for every possible combination of clusters containing a sulfuric acid molecule, a formic acid molecule, a nitric acid molecule, an ammonia molecule, a dimethylamine molecule, and 0–5 water molecules, we have completed an exhaustive search of the DLPNO-CCSD(T)/CBS//ωB97X-D/6-31++G** Gibbs free energy surface for this system. We find that the detailed geometries of each minimum free energy cluster are often more important than traditional acid or base strength. Addition of a water molecule to a dry cluster can enhance stabilization, and we find that the (SA)(NA)(A)(DMA)(W) cluster has special stability. Equilibrium calculations of SA, FA, NA, A, DMA, and water using our quantum chemical Δ G ° values for cluster formation and realistic estimates of the concentrations of these monomers in the atmosphere reveals that nitric acid can drive early stages of particle formation just as efficiently as sulfuric acid. Our results lead us to believe that particle formation in the atmosphere results from the combination of many different molecules that are able to form highly stable complexes with acid molecules such as SA, NA, and FA. 

   more » « less