Methane steam reforming over Ni/Ce–ZrO2 catalyst: Influences of Ce–ZrO2 support on reactivity, resistance toward carbon formation, and intrinsic reaction kinetics

2005 ◽  
Vol 290 (1-2) ◽  
pp. 200-211 ◽  
Author(s):  
N. Laosiripojana ◽  
S. Assabumrungrat
Keyword(s):  
Reaction Kinetics ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Carbon Formation ◽  
Methane Steam ◽  
Zro2 Catalyst

Effect of ceria loading on the carbon formation during low temperature methane steam reforming over a Ni/CeO2/ZrO2 catalyst

2008 ◽  
Vol 95 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Anton Purnomo ◽  
Susan Gallardo ◽  
Leonila Abella ◽  
Chris Salim ◽  
Hirofumi Hinode
Keyword(s):  
Low Temperature ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Carbon Formation ◽  
Methane Steam ◽  
Zro2 Catalyst

Methane steam reforming for hydrogen production using low water-ratios without carbon formation over ceria coated Ni catalysts

2008 ◽  
Vol 345 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Jiahui Xu ◽  
Connie M.Y. Yeung ◽  
Jun Ni ◽  
Frederic Meunier ◽  
Nadia Acerbi ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Carbon Formation ◽  
Ni Catalysts ◽  
Methane Steam

An Analysis of Heat Transfer Processes in an Internal Indirect Reforming Type Solid Oxide Fuel Cell

2010 ◽  
Author(s):  
Grzegorz Brus ◽  
Zygmunt Kolenda ◽  
Shinji Kimijima ◽  
Janusz S. Szmyd
Keyword(s):  
Steam Reforming ◽  
Solid Oxide ◽  
Methane Steam Reforming ◽  
Oxide Fuel ◽  
Carbon Formation ◽  
Internal Reforming ◽  
Thermal Boundary Conditions ◽  
Methane Steam ◽  
Fuel Flow ◽  
Metal Support

This paper presents experimental and numerical studies on the fuel reforming process on an Ni/YSZ catalyst. Nickel is widely known as a catalyst material for Solid Oxide Fuel Cells. Because of its prices and catalytic properties, Ni is used in both electrodes and internal reforming reactors. However, using Ni as a catalyst carries some disadvantages. Carbon formation is a major problem during a methane/steam reforming reaction based on Ni catalysis. Carbon formation occurs between nickel and metal-support, creating fibers which damage the catalytic property of the reactor. To prevent carbon deposition, the steam-to-carbon ratio is kept between 3 and 5 throughout the entire process. To optimize the reforming reactors, detailed data about the entire reforming process is required. In the present paper kinetics of methane/steam reforming on the Ni/YSZ catalyst was experimentally investigated. Measurements including different thermal boundary conditions, the fuel flow rate and the steam-to-methane ratios were performed. The reforming rate equation derived from experimental data was used in the numerical model to predict synthetic gas composition at the outlet of the reformer.

scholarly journals Catalysts for Methane Steam Reforming Reaction: Evaluation of CeO2 Addition to Alumina-Based Washcoat Slurry Formulation

2020 ◽  
Vol 6 (3) ◽  
pp. 52 ◽  
Author(s):  
Vincenzo Palma ◽  
Eugenio Meloni ◽  
Simona Renda ◽  
Marco Martino
Keyword(s):  
Steam Reforming ◽  
Methane Conversion ◽  
Formation Rate ◽  
Coke Formation ◽  
Methane Steam Reforming ◽  
Mechanical Resistance ◽  
Carbon Formation ◽  
Structured Catalyst ◽  
Methane Steam ◽  
Adherence Test

The effect of the addition of CeO2 to alumina-based washcoat slurry formulation on the methane steam reforming (MSR) reaction was investigated. Five Al2O3-CeO2-based washcoat slurries, differing from each other in the Al2O3/CeO2 ratio (nominal ratio equal to ∞, 0.042, 0.087, 0.250, 0.667) were prepared, dried and calcined; the resulting powders were loaded with nickel as an active metal and the obtained catalysts were tested in MSR reaction. Five cylindrical silicon carbide (SiC) monoliths were washcoated with the prepared slurries and their mechanical resistance was evaluated through the ultrasound adherence test. The activity tests results highlighted the best performance in terms of methane conversion and hydrogen selectivity of the powder catalyst, with the Al2O3/CeO2 percentage nominal ratio equal to 0.042. A structured catalyst was finally prepared by loading a SiC monolith with the most active catalytic formulation and tested in MSR reaction. The performance of the structured catalyst was evaluated in terms of methane conversion and its stability was verified in a time-on-stream test, which allowed for the evaluation of the carbon formation rate; furthermore, its activity was characterized by the estimation of the kinetic parameters. The results highlighted the beneficial effect of ceria addition on the catalytic activity; moreover, compared with data of the literature, the calculated carbon formation rate demonstrated a good resistance of the catalyst to coke formation.

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>

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