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Page 87
Analytica 2016
September 28-30, 2016
Volume 7, Issue 5(Suppl) J Anal Bioanal Tech 2016
ISSN: 2155-9872 JABT, an open access journal
conferenceseries .com
September 28-30, 2016 Orlando, USA
7th International Conference and Exhibition on
Analytical & Bioanalytical Techniques
J Anal Bioanal Tech 2016, 7:5(Suppl)
Quantum chemistry aided FTIR spectroscopy to distinguish internal and external Brønsted acidic
sites of zeolite nano-crystals
Istvan Halasz
PQ Corporation, USA
Microporous nano-crystals of zeolites are key ingredients in more than 50% of heterogeneous catalysts, which contribute
to manufacturing the majority of chemical products. Their Brønsted acidic hydroxyl groups (BA-OH) play pivotal role
in many reactions. The presence of BA-OH sites on the crystallite surface bears of special interest, due to diffusion limitations
inside of their micropores. Yet distinction of the internal and external BA-OH sites has been ambiguous. Here we show
that clear distinction can be made by Fourier Transform Infrared (FTIR) spectroscopy when both diffuse reflectance (DR)
and transmission (TR) sampling techniques are employed. Different laboratories use these techniques interchangeably for
characterizing solids. To our surprise, we observed very different BA-OH spectra on some zeolites when measured by these
two methods. Since physical and chemical differences do not generate such large spectral deviations, we conjectured that
emphasized vibrational intensities of the surface and bulk BA-OH groups cause the differences when DR or TR technique is
used, respectively. To prove our point we performed selective pyridine adsorption experiments on Chabazite (H-CHA) and
H-SAPO-34 zeolites and also computed the density functional theory (DFT) based FTIR spectra of their four geometrically
different BA-OH groups in the bulk and on the surface, which confirmed the conjectured vibrational differences. These zeolites
are key ingredients of new catalysts for diesel-automobile exhaust control and for the methanol to olefin, MTO, technology.
Direct-writing of paper based conductive track using silver nano-ink for eletrochemical application
Kamlesh Shrivas
Guru Ghasidas Vishwavidyalaya, India
To the best of our knowledge, to date there is no report for the synthesis of silver nanoparticles capped with oleylamine
(AgNPs/OLA) and then use of NPs in the preparation of paper based conductive track for electroanalytical application. The
synthesized OLA capped AgNPs was characterized with TEM, UV-visible, EDX, FTIR and TGA to know the size, composition
and surface modification of NPs. The best electrical conductivity of printed electronic (0.11x 105 S cm-1) was obtained by
applying a 10% AgNPs nano-ink solution on photo paper while keeping sintering temperature at 150oC for 60 min of sintering
time. A conductive nano-ink was used to prepare electrodes (counter, reference and working) on photo paper and utilized
in cyclic voltammetry (CV) measurement. In addition, we demonstrated the lighting of LED when conductive track was
connected to a 1.5 V battery. The advantages of this paper-based flexible electrodes are user-friendly, cost effective and multiple
analyses (> 50 times) in CV compared to other printed electrodes.