Design of Anode Materials for IT SOFC: Effect of Complex Oxide Promoters and Pt Group Metals on Activity and Stability in Methane Steam Reforming of Ni/YSZ (ScSZ) Cermets

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Vladislav A. Sadykov ◽  
Natalia V. Mezentseva ◽  
Rimma V. Bunina ◽  
Galina M. Alikina ◽  
Anton I. Lukashevich ◽  
...  
Keyword(s):  
Steam Reforming ◽  
High Performance ◽  
Precious Metals ◽  
Complex Oxide ◽  
Intermediate Temperature ◽  
Methane Steam Reforming ◽  
Oxygen Mobility ◽  
Media Effect ◽  
Intermediate Temperature Range ◽  
Methane Steam

Ni/YSZ or Ni/ScCeSZ cermets were promoted by up to 10 wt % of fluoritelike (Pr–Ce–Zr–О, La–Ce–Zr–О, and Ce–Zr–О) or perovskitelike (La–Pr–Mn–Cr–O) oxides and small (up to 1.4 wt %) amounts of Pt group metals (Pd, Pt, or Ru). Reactivity of samples, their lattice oxygen mobility, and their ability to activate methane were characterized by temperature-programed reduction by CH4. The catalytic properties of these samples in methane steam reforming were studied at 500–850°C and short contact times (10 ms) in feeds with 8 mol % of CH4 and steam/methane ratio of 1:3. Oxide promoters ensure stable performance of cermets in stoichiometric feeds at T>650°C by suppressing carbon deposition. Copromotion with precious metals enhances performance in the intermediate temperature (450–600°C) range due to more efficient activation of methane. Factors determining specificity of these cermet materials’ performance (chemical composition, microstructure, oxygen mobility in oxides, interaction between components, and reaction media effect) are considered. The most promising systems for practical application are Pt/Pr–Ce–Zr–O/Ni/YSZ and Ru/La–Pr–Mn–Cr–O/Ni/YSZ cermets demonstrating a high performance in the intermediate temperature range under broad variation in steam/CH4 ratio.

Design of Anodes for IT SOFC: Effect of Complex Oxide Promoters and Pd on Activity and Stability in Methane Steam Reforming of Ni/YSZ (ScSZ) Cermets

2006 ◽  
Vol 972 ◽  
Author(s):  
Vladislav A Sadykov ◽  
Natalia V Mezentseva ◽  
Rimma v Bunina ◽  
Galina M Alikina ◽  
Anton I Lukashevich ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Steam Reforming ◽  
Complex Oxide ◽  
Solid Oxide ◽  
Coke Deposition ◽  
Methane Steam Reforming ◽  
Oxide Fuel ◽  
Oxygen Mobility ◽  
Methane Steam ◽  
Spatial Uniformity

AbstractEffect of fluorite-like or perovskite-like complex oxide promoters and Pd on the performance of Ni/YSZ and Ni/ScSZ cermets in methane steam reforming or selective oxidation by O2 into syngas at short contact times was studied. Spatial uniformity of dopants distribution in composites was controlled by TEM combined with EDX, while the lattice oxygen mobility and reactivity was elucidated by CH4 and H2 TPR. Oxide promoters allow to operate even at stoichiometric H2O/CH4 ratio by suppressing coke deposition through modification of Ni surface, while doping by Pd ensures reasonable performance at moderate (∼550 °C) temperatures required for Intermediate–Temperature Solid Oxide Fuel Cells (IT SOFC).

Ultra-Low Amounts of Palladium (0.005-0.05 Wt% Pd) Supported on Titania: Remarkable Low-Temperature Activity for NO Reduction with CO and Structure-Function Property Relationships in Methane Oxidation

2020 ◽  
Author(s):  
Konstantin Khivantsev ◽  
Libor Kovarik ◽  
Nicholas R. Jaegers ◽  
János Szanyi ◽  
Yong Wang
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Methane Oxidation ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Oxide Reduction ◽  
Water Steam ◽  
Methane Steam ◽  
Anatase Titania ◽  
Nitric Oxide Reduction

<p>Atomically dispersed Pd +2 cations with ultra-dilute loading of palladium (0.005-0.05 wt%) were anchored on anatase titania and characterized with FTIR, microscopy and catalytic tests. CO infrared adsorption produces a sharp, narrow mono-carbonyl Pd(II)-CO band at ~2,130 cm<sup>-1</sup> indicating formation of highly uniform and stable Pd+2 ions on anatase titania. The 0.05 wt% Pd/TiO<sub>2</sub> sample was evaluated for methane combustion under dry and wet (industrially relevant) conditions in the presence and absence of carbon monoxide. Notably, we find the isolated palladium atoms respond dynamically upon oxygen concentration modulation (switching-on and switching off). When oxygen is removed from the wet methane stream, palladium ions are reduced to metallic state by methane and catalyze methane steam reforming instead of complete methane oxidation. Re-admission of oxygen restores Pd<sup>+2</sup> cations and switches off methane steam reforming activity. Moreover, 0.05 wt% Pd/TiO<sub>2</sub> is a competent CO oxidation catalyst in the presence of water steam with 90% CO conversion and TOF ~ 4,000 hr<sup>-1</sup> at 260 ⁰C. </p><p>More importantly, we find that diluting 0.05 wt% Pd/titania sample with titania to ultra-low 0.005 wt% palladium loading produces a remarkably active material for nitric oxide reduction with carbon monoxide under industrially relevant conditions with >90% conversion of nitric oxide at 180 ⁰C (~460 ppm NO and 150 L/g*hr flow rate in the presence of >2% water steam) and TOF ~6,000 hr<sup>-1</sup>. Pd thus outperforms state-of-the-art rhodium containing catalysts with (15-20 times higher rhodium loading; rhodium is ~ 3 times more expensive than palladium). Furthermore, palladium catalysts are more selective towards nitrogen and produce significantly less ammonia relative to the more traditional rhodium catalysts due to lower Pd amount nd lower water-gas-shift activity. Our study is the first example of utilizing ultra-low (0.05 wt% and less) noble metal (Pd) amounts to produce heterogeneous catalysts with extraordinary activity for nitric oxide reduction. This opens up a pathway to study other Pd, Pt and Rh containing materials with ultra-low loadings of expensive noble metals dispersed on titania or titania-coated oxides for industrially relevant nitric oxide abatement.</p>

scholarly journals DFT Benchmark Studies on Representative Species and Poisons of Methane Steam Reforming on Ni(111)

2021 ◽  
Author(s):  
Sai Sharath Yadavalli ◽  
Glenn Jones ◽  
Michail Stamatakis
Keyword(s):  
Steam Reforming ◽  
Graphitic Carbon ◽  
Methane Steam Reforming ◽  
Ni Catalysts ◽  
Methane Steam ◽  
Representative Species ◽  
Industrial Operations ◽  
Major Impediment ◽  
Carbon Based

Ni catalysts used in Methane Steam Reforming (MSR) are highly susceptible to poisoning by carbon-based species, which poses a major impediment to the productivity of industrial operations. These graphitic carbon-like...

scholarly journals Retraction: Computational fluid dynamics modeling of the millisecond methane steam reforming in microchannel reactors for hydrogen production

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12531-12531
Author(s):  
Junjie Chen ◽  
Xuhui Gao ◽  
Longfei Yan ◽  
Deguang Xu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Hydrogen Production ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Dynamics Modeling ◽  
Computational Fluid Dynamics Modeling ◽  
Microchannel Reactors ◽  
Methane Steam

Retraction of ‘Computational fluid dynamics modeling of the millisecond methane steam reforming in microchannel reactors for hydrogen production’ by Junjie Chen et al., RSC Adv., 2018, 8, 25183–25200, DOI: 10.1039/C8RA04440F.

scholarly journals Methane steam reforming at low steam-to-carbon ratio: The effect of Y doping in Rh substituted lanthanum zirconates

2020 ◽  
Vol 606 ◽  
pp. 117802
Author(s):  
Yan Zhou ◽  
Daniel Haynes ◽  
John Baltrus ◽  
Amitava Roy ◽  
Dushyant Shekhawat ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Methane Steam

Methane steam reforming in a Pd-Ru membrane reactor

2000 ◽  
Vol 17 (3) ◽  
pp. 288-291 ◽  
Author(s):  
Suk Woo Nam ◽  
Sung Pil Yoon ◽  
Heung Yong Ha ◽  
Seong-Ahn Hong ◽  
Anatoly P. Maganyuk
Keyword(s):  
Steam Reforming ◽  
Membrane Reactor ◽  
Methane Steam Reforming ◽  
Methane Steam
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