Advancing Time-resolved Methods in Monitoring and Characterization of Catalysts

Applying Dynamic and Synchronous DRIFTS/EXAFS to the Structural Reactive Behaviour of Dilute (≤1 wt%) Supported Rh/Al2O3 Catalysts using Quick and Energy Dispersive EXAFS

“…The author is given to understand (and sincerely hopes) that other resources of this nature are planned elsewhere, and will pass into the realm of accessible user facilities in the relatively near future. Further information regarding this new type of QUEXAFS resource can be found in [58,59] or (http://sls.web.psi.ch/view.php/beamlines/superxas/). processes, and materials research in general.…”

Introduction to X-Ray Absorption Spectroscopy

“…The scanning speed is thus limited by the time needed to move and settle the monochromator and to measure the signal. In contrast, scanning times can be dramatically reduced by using a monochromator moving with constant velocity and fast data acquisition systems [18,19]. A full scan performed with such a quickXAS setup may take tens of seconds compared to 30-60 minutes for conventional scans.…”

“…A full scan performed with such a quickXAS setup may take tens of seconds compared to 30-60 minutes for conventional scans. Even faster measurements in the order of one second or less can be realized by energy dispersive XAS where a polychromatic beam is incident on the sample and then diverges onto a position sensitive detector such as a photodiode array [18,19]. The spectrum is thus recorded simultaneously and the time needed is limited only by the response time of the detector and the number of scans required for a sufficient signal to noise ratio.…”

The Inner Shell Spectroscopy beamline at NSLS-II: a facility for in situ and operando X-ray absorption spectroscopy for materials research

“…The second strategy, the quick-EXAFS (QEXAFS) approach, is based on rapid continuous scans through the relevant energy range by oscillating the monochromator around the selected Bragg angle. QEXAFS motion schemes have been realized with traditional monochromators based on goniometers (Lee et al, 1998;Oji et al, 2012;Nikitenko et al, 2008;Clausen et al, 1993;Dent et al, 2013;Martel et al, 2012;Uruga et al, 2009;Prestipino et al, 2011), piezoelectric tilttables (Frahm et al, 2009;Lu ¨tzenkirchen-Hecht et al, 2001;Bornebusch et al, 1999;Richwin et al, 2001), and cam-shaft driven designs with the latter demonstrating the best performance in terms of stability, motion reproducibility, and scanning speed (Fonda et al, 2012;Frahm et al, 2004;Sto ¨tzel et al, 2010;La Fontaine et al, 2013). While these designs improve the temporal resolution of XAS experiments down to the millisecond regime, they usually allow only sinusoidal motion around the absorption edge of interest.…”