caa a22 4500 606173889 CHVBK 20210128100735.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s11244-015-0383-z doi (NATIONALLICENCE)springer-10.1007/s11244-015-0383-z The Effect of Adsorbed Molecule Gas-Phase Deprotonation Enthalpy on Ion Exchange in Sodium Exchanged Zeolites: An In Situ FTIR Investigation [Elektronische Daten] [Brian Murphy, Mark Davis, Bingjun Xu] Molecular-level understanding of the interactions between reactants and the surface of solid catalysts is of importance to the rational design of catalysts. Here, in situ transmission Fourier transform infrared spectroscopy is employed to investigate the ion exchange between the acidic hydrogen in organic molecules that have been adsorbed from the gas phase and sodium cations in zeolites. Organic compounds with functional groups common among key biomass-derived compounds are used as probe molecules. We demonstrate that ion exchange between acidic hydrogen in organic molecules and the sodium cations in zeolites with the FAU topology produces Brønsted acid sites and the corresponding adsorbed salt species by identifying signature spectroscopic bands. Furthermore, the gas-phase deprotonation enthalpy (GPDE) of the organic compounds is identified as a key descriptor in determining the feasibility and extent of the exchange process. Molecules with GPDE below 1462kJ/mol, e.g., m-cresol (1462kJ/mol), propanoic acid (1454), acetic acid (1457), acrylic acid (1440) and trifluoroacetic acid (1357), show clear vibrational bands for Brønsted acid sites and the corresponding sodium salts, while molecules with higher GPDE, such as trifluoroethanol (1513), ethanol (1586), and water (1622) do not. These data indicate that the degree of dissociation of the acidic hydrogen is a key element in the ion exchange. The generality of this process in zeolites is established by the observation of similar results on zeolites with differing topologies (FAU, MFI, *BEA, and MOR). Springer Science+Business Media New York, 2015 Vibrational spectroscopy nationallicence Ion-exchange nationallicence Gas-phase deprotonation nationallicence Zeolites nationallicence Murphy Brian Department of Chemical and Biomolecular Engineering, Catalysis Center for Energy Innovation, University of Delaware, 150 Academy Street, 19716, Newark, DE, USA aut Davis Mark Chemical Engineering, California Institute of Technology, 91125, Pasadena, CA, USA aut Xu Bingjun Department of Chemical and Biomolecular Engineering, Catalysis Center for Energy Innovation, University of Delaware, 150 Academy Street, 19716, Newark, DE, USA aut Topics in Catalysis Springer US; http://www.springer-ny.com 58/7-9(2015-05-01), 393-404 1022-5528 58:7-9<393 2015 58 11244 https://doi.org/10.1007/s11244-015-0383-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11244-015-0383-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Murphy Brian Department of Chemical and Biomolecular Engineering, Catalysis Center for Energy Innovation, University of Delaware, 150 Academy Street, 19716, Newark, DE, USA aut NATIONALLICENCE 700 1- Davis Mark Chemical Engineering, California Institute of Technology, 91125, Pasadena, CA, USA aut NATIONALLICENCE 700 1- Xu Bingjun Department of Chemical and Biomolecular Engineering, Catalysis Center for Energy Innovation, University of Delaware, 150 Academy Street, 19716, Newark, DE, USA aut NATIONALLICENCE 773 0- Topics in Catalysis Springer US; http://www.springer-ny.com 58/7-9(2015-05-01), 393-404 1022-5528 58:7-9<393 2015 58 11244