DRIFTS transform spectroscopy

Diffuse Reflectance IR Fourier Transform Spectroscopy (DRIFTS) can be employed with high surface area catalytic samples that are not sufficiently transparent to be studied in transmission. In this technique, the diffusely scattered IR radiation from a sample is collected, refocussed, and analysed. Samples can be measured in the form of loose powders. [Pg.41]

Although acetone was a major product, it was not observed by infrared spectroscopy. Flowing helium/acetone over the catalyst at room temperature gave a prominent carbonyl band at 1723 cm 1 (not show here). In this study, a DRIFTS (diffuse reflectance infrared Fourier transform spectroscopy) cell was placed in front of a fixed reactor DRIFTS only monitored the adsorbed and gaseous species in the front end of the catalyst bed. The absence of acetone s carbonyl IR band in Figure 3 and its presence in the reactor effluent suggest the following possibilities (i) acetone formation from partial oxidation is slower than epoxidation to form PO and/or (ii) acetone is produced from a secondary reaction of PO. [Pg.407]

The experimental system consists of three sections (i) a gas metering section with interconnected 4-port and 6-port valves, (ii) a reactor section including an in-situ diffused reflectance infrared Fourier transform spectroscopy reactor (DRIFTS) connected to tubular quartz reactor, (iii) an effluent gas analysis section including a mass spectrometer or a gas chromatograph (9). [Pg.410]

In this contribution, the steady-state isotopic transient kinetic analysis-diffuse reflectance Fourier transform spectroscopy (SSITKA-DRIFTS) method provides further support to the conclusion that not only are infrared active formates likely intermediates in the water-gas shift (WGS) reaction, in agreement with the mechanism proposed by Shido and Iwasawa for Rh/ceria, but designing catalysts based on formate C-H bond weakening can lead to significantly higher... [Pg.365]

In the diffuse reflectance mode, samples can be measured as loose powders, with the advantages that not only is the tedious preparation of wafers unnecessary but also diffusion limitations associated with tightly pressed samples are avoided. Diffuse reflectance is also the indicated technique for strongly scattering or absorbing particles. The often-used acronyms DRIFT or DRIFTS stand for diffuse reflectance infrared Fourier transform spectroscopy. The diffusely scattered radiation is collected by an ellipsoidal mirror and focussed on the detector. The infrared absorption spectrum is described the Kubelka-Munk function ... [Pg.224]

Diffuser aerators, jet air, 26 165 Diffuse reflectance, 14 231 Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), 24 72, 110-111... [Pg.268]

DRIFT spectra, acquiring, 24 111. See also Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) Drilling, of hydrothermal wells, 12 525-527 Drilling fluid (drilling mud) companies, 9 2 Drilling fluid materials, 9 2, 9-25. See also Drilling fluids Drilling muds alkalinity control in, 9 19 barite, 9 9-10 calcite, 9 10... [Pg.289]

Direct NIR or MIR measurements of whole soil can be made using attenuated total reflectance (ATR) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) samplers. This type of measurement detects only components on the surface and so has severe limitations when information about the bulk soil is needed [4],... [Pg.179]

Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is used to obtain spectra of powders and rough polymeric surfaces such as textiles and paper. IR radiation is focused onto the surface of the sample in a cup resulting in both specular reflectance (which directly reflects off the surface having equal angles of incidence and reflectance) and diffuse reflectance (which penetrates into the sample subsequently scattering in all angles). Special mirrors allow the specular reflectance to be minimized. [Pg.426]

DRIFTS diffuse reflectance infrared Fourier transform spectroscopy... [Pg.266]

Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFT).6 When IR radiation is directed onto the surface of a solid sample, two types of energy reflectance can occur specular and diffuse. The specular component is the radiation that reflects directly off the sample surface (i.e., not absorbed by the sample). Diffuse reflectance is the radiation that penetrates into the sample and then emerges. Diffuse reflectance accessories are designed to optimize the diffuse reflected energy and suppress the specular component. The optics therefore selectively directs the scattered radiation to the IR detector. [Pg.223]

Chan, T. Y. Chen, R. Sofia, M. J. Smith, B. C. Glennon, D. High Throughput On-Bead Monitoring of Solid Phase Reactions by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), Tetrahedron Lett. 1997, 38, 2821. [Pg.244]

Cradun, R., Miller, D.J., Dulamita, N. and Jackson, J.E. (1996) Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) applied in heterogeneous catalysis studies. Prog. Catal., 5, 55. [Pg.182]

Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS)... [Pg.230]

The heterogenization of MAO-activated Nd(z 3-C3H5)3 dioxane on MAO-functionalized Si(>2 was reported by T. Riihmer et al. [307]. In situ DRIFT (= diffuse reflectance infrared Fourier transform) spectroscopy and TPRS (= temperature-programmed reaction spectroscopy) were employed... [Pg.238]

Therefore, X-ray photoelectron spectroscopy (XPS) [12, 16,17] and diffuse reflection infrared Fourier transform spectroscopy (DRIFT) [17] are used to analyse the chemical composition of the metal surface and the amount of the surface-bonded polymer after the adsorption processes. For the ZnO/PVFA-co-PVAm composites solvatochromic dyes were employed to evaluate changes in the surface polarity after the polymer adsorption [18-22],... [Pg.111]

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