Low-Temperature Water–Gas Shift: Effects of Y and Na in High Surface Area Na-Doped, YSZ-Supported Pt Catalysts

2016 ◽  
pp. 309-326
Author(s):  
Michela Martinelli ◽  
Gary Jacobs ◽  
Uschi Graham ◽  
Wilson Shafer ◽  
Carlo Visconti ◽  
...  
Keyword(s):  
Low Temperature ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Water Gas Shift ◽  
Pt Catalysts ◽  
Supported Pt Catalysts ◽  
Water Gas ◽  
Temperature Water

scholarly journals Low Temperature Water-Gas Shift: Enhancing Stability through Optimizing Rb Loading on Pt/ZrO2

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 210
Author(s):  
Caleb Daniel Watson ◽  
Michela Martinelli ◽  
Donald Charles Cronauer ◽  
A. Jeremy Kropf ◽  
Gary Jacobs
Keyword(s):  
Low Temperature ◽  
Hydrogen Transfer ◽  
Water Gas Shift ◽  
Significant Shift ◽  
Catalyst Activation ◽  
X Ray ◽  
Temperature Programmed ◽  
Water Gas ◽  
X Ray Absorption ◽  
Temperature Water

Recent studies have shown that appropriate levels of alkali promotion can significantly improve the rate of low-temperature water gas shift (LT-WGS) on a range of catalysts. At sufficient loadings, the alkali metal can weaken the formate C–H bond and promote formate dehydrogenation, which is the proposed rate determining step in the formate associative mechanism. In a continuation of these studies, the effect of Rb promotion on Pt/ZrO2 is examined herein. Pt/ZrO2 catalysts were prepared with several different Rb loadings and characterized using temperature programmed reduction mass spectrometry (TPR-MS), temperature programmed desorption (TPD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), an X-ray absorption near edge spectroscopy (XANES) difference procedure, extended X-ray absorption fine structure spectroscopy (EXAFS) fitting, TPR-EXAFS/XANES, and reactor testing. At loadings of 2.79% Rb or higher, a significant shift was seen in the formate ν(CH) band. The results showed that a Rb loading of 4.65%, significantly improves the rate of formate decomposition in the presence of steam via weakening the formate C–H bond. However, excessive rubidium loading led to the increase in stability of a second intermediate, carbonate and inhibited hydrogen transfer reactions on Pt through surface blocking and accelerated agglomeration during catalyst activation. Optimal catalytic performance was achieved with loadings in the range of 0.55–0.93% Rb, where the catalyst maintained high activity and exhibited higher stability in comparison with the unpromoted catalyst.

Low temperature water–gas shift: comparison of thoria and ceria catalysts

2004 ◽  
Vol 267 (1-2) ◽  
pp. 27-33 ◽  
Author(s):  
Gary Jacobs ◽  
Adam Crawford ◽  
Leann Williams ◽  
Patricia M Patterson ◽  
Burtron H Davis
Keyword(s):  
Low Temperature ◽  
Water Gas Shift ◽  
Ceria Catalysts ◽  
Water Gas ◽  
Temperature Water
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