High pressure reaction cell

The implementation of high-pressure reaction cells in conjunction with UFIV surface science techniques allowed the first tme in situ postmortem studies of a heterogeneous catalytic reaction. These cells penult exposure of a sample to ambient pressures without any significant contamination of the UFIV enviromnent. The first such cell was internal to the main vacuum chamber and consisted of a metal bellows attached to a reactor cup [34]- The cup could be translated using a hydraulic piston to envelop the sample, sealing it from... 

UHV-high-pressure reaction cell are preferable. Such an instrument that has been successfully applied for several years is shown in Fig. 8 (48,84,118). The UHV section (lx 10 mbar) is equipped with tools for sample preparation (Ar ion gun, metal evaporator, quartz crystal microbalance) as well as sample characterization by FEED, AES, and thermal desorption spectroscopy (TDS). After analysis of the model catalysts under UHV, the samples are transferred (still under UHV) to the SFG cell. When the manipulator is lowered to the SFG level, the sample holder is... 

Fig. 9. An SFG-compatible UHV high-pressure reaction cell that allows the performance of 2-IR 1-vis SFG experiments (48,160). Three noncollinear laser beams (two IR, one visible beam) are spatially and temporally overlapped on the adsorbate/substrate interface, which allows simultaneous monitoring of two different spectral regions (reflected pump beams are not shown).

B.2. High-Pressure Reaction Cells for PM-IRAS and Experimental Design... 

Fig. 11. (a) Experimental apparatus combining a UHV surface analysis chamber with a UHV-high-pressure reaction cell optimized for PM-IRAS spectroscopy. Pre- and post-reaction surface analysis under UHV can be performed by XPS, LEED, AES, and TDS. The optical equipment and the high-pressure cell used for the PM-IRAS experiments are shown in (b) 84,113,114,171). 

Rupprechter G, Dellwig T, Unterhalt H, Freund H-J (2001). CO adsorption on Ni(lOO) and Pt(l 11) studied by infrared-visible sum frequency generation spectroscopy design and application of an SFG-compatible UHV-high-pressure reaction cell. Top Catal, 15, 19... 

Bare, S.R., Yang, N., Kelly, S.D. and Mickelson, G.E. (2007) Design and operation of a high pressure reaction cell for in situ X-ray absorption spectroscopy. Catal. Today, 126, 18-26. 

The sulfation experiments were performed in a custom tractable high-pressure reaction cell [14] mounted in situ with a Perkin Elmer 545 Scanning Auger Microprobe. The effects of reaction conditions and catalyst composition were examined is a function of sulfur dioxide (SO2) exposure. Specifically, exposure to SO2 was examined as a function of sample composition (100 at.% cerium - Oat. % cerium), reaction pressure (1 Torr - 1000 Torr), and catalyst temperature (200 K - 1003 K), as outlined in Table 1. 

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