scholarly journals Highly Active Catalysts Based on the Rh4(CO)12 Cluster Supported on Ce0.5Zr0.5 and Zr Oxides for Low-Temperature Methane Steam Reforming

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 800 ◽  
Author(s):  
Andrea Fasolini ◽  
Silvia Ruggieri ◽  
Cristina Femoni ◽  
Francesco Basile
Keyword(s):  
Low Temperature ◽  
Steam Reforming ◽  
Supported Catalysts ◽  
Supported Catalyst ◽  
Methane Steam Reforming ◽  
Small Scale ◽  
Methane Reforming ◽  
Hydrogen Purification ◽  
Highly Active ◽  
Reforming Reactions

Syngas and Hydrogen productions from methane are industrially carried out at high temperatures (900 °C). Nevertheless, low-temperature steam reforming can be an alternative for small-scale plants. In these conditions, the process can also be coupled with systems that increase the overall efficiency such as hydrogen purification with membranes, microreactors or enhanced reforming with CO2 capture. However, at low temperature, in order to get conversion values close to the equilibrium ones, very active catalysts are needed. For this purpose, the Rh4(CO)12 cluster was synthetized and deposited over Ce0.5Zr0.5O2 and ZrO2 supports, prepared by microemulsion, and tested in low-temperature steam methane reforming reactions under different conditions. The catalysts were active at 750 °C at low Rh loadings (0.05%) and outperformed an analogous Rh-impregnated catalyst. At higher Rh concentrations (0.6%), the Rh cluster deposited on Ce0.5Zr0.5 oxide reached conversions close to the equilibrium values and good stability over long reaction time, demonstrating that active phases derived from Rh carbonyl clusters can be used to catalyze steam reforming reactions. Conversely, the same catalyst suffered from a fast deactivation at 500 °C, likely related to the oxidation of the Rh phase due to the oxygen-mobility properties of Ce. Indeed, at 500 °C the Rh-based ZrO2-supported catalyst was able to provide stable results with higher conversions. The effects of different pretreatments were also investigated: at 500 °C, the catalysts subjected to thermal treatment, both under N2 and H2, proved to be more active than those without the H2 treatment. In general, this work highlights the possibility of using Rh carbonyl-cluster-derived supported catalysts in methane reforming reactions and, at low temperature, it showed deactivation phenomena related to the presence of reducible supports.

Silica Sol-Gel Supported Nickel Nano-Catalyst for Hydrogen Production Using Microreactors

2005 ◽  
Vol 885 ◽  
Author(s):  
Krithi Shetty ◽  
Shihuai Zhao ◽  
Wei Cao ◽  
Naidu V. Seetala ◽  
Debasish Kuila
Keyword(s):  
Steam Reforming ◽  
Average Pore Size ◽  
Sol Gel ◽  
Supported Catalyst ◽  
Silica Sol ◽  
Average Pore ◽  
Steam Reforming Of Methanol ◽  
Nano Catalyst ◽  
Before And After ◽  
Reforming Reactions

ABSTRACTThe goal of this research is to investigate the activities of a non-noble nano-catalyst (Ni/SiO2) using Si-microreactors for steam reforming of methanol to produce hydrogen for fuel cells. The supported catalyst was synthesized by sol-gel method using Ni (II) salts and Si(C2H5O)4 as starting materials. EDX results indicate that the actual loading of Ni (5-6%) is lower than the intended loading of 12 %. The specific surface area of the silica sol-gel encapsulated Ni nano-catalyst is 452 m2/g with an average pore size of ∼ 3 nm. Steam reforming reactions have been carried out in a microreactor with 50 µm channels in the temperature range of 180-240 °C and atmospheric pressure. Results show 53% conversion of methanol with a selectivity of 74 % to hydrogen at 5 l/min and 200 °C. The magnetic properties of the catalysts were performed using a Vibrating Sample Magnetometer (VSM) to study the activity of the catalysts before and after the steam reforming reactions. The VSM results indicate much higher activity in the microreactor compared to macro-reactor and Ni forms non-ferromagnetic species faster in the microreactor.

scholarly journals Catalytic Activity of Oxidation-Reduction Pre-Treated Ni3Al for Methane Steam Reforming

2010 ◽  
Vol 89-91 ◽  
pp. 645-650 ◽  
Author(s):  
Ya Xu ◽  
Dong Hyun Chun ◽  
Jun Hyuk Jang ◽  
Masahiko Demura ◽  
Dang Moon Wee ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Steam Reforming ◽  
Active Surface ◽  
Methane Steam Reforming ◽  
Reduction Treatment ◽  
Highly Active ◽  
Methane Steam ◽  
Oxidation Reduction ◽  
Pre Treatment ◽  
Oxidation In Air

The catalytic activity of oxidation-reduction pre-treated Ni3Al powder for methane steam reforming was examined. The oxidation-reduction pre-treatment consisted of two steps: oxidation in air at various temperatures from 973 to 1373 K, and then followed by reduction in H2 at 873 K. It was found that the oxidation-reduction treatments significantly reduced the onset temperature of activity, i.e., improved the activity of Ni3Al powder at low temperatures. The characterization of Ni3Al surface showed that an outer surface layer of fine NiO particles were formed on the surface of Ni3Al after oxidation. These NiO particles were reduced to metallic Ni by the subsequent reduction treatment, resulting in the high activity for methane steam reforming. These results indicate that the Ni3Al can form highly active surface structure with oxidation-reduction treatment, having excellent heat resistance.

Technological Aspects of Ethanol Steam Reforming Processors for Molten Carbonate Fuel Cells

2006 ◽  
Author(s):  
S. Freni ◽  
F. Frusteri ◽  
N. Mondello ◽  
V. Chiodo ◽  
S. Siracusano ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Supported Catalysts ◽  
Catalyst Activity ◽  
Supported Catalyst ◽  
Molten Carbonate Fuel Cell ◽  
Water Mixture ◽  
Molten Carbonate ◽  
Carbon Formation ◽  
Molten Carbonate Fuel Cells ◽  
Catalytic Behaviour

Bioethanol, obtained by biomass fermentation, could be an important hydrogen supplier as a renewable source. The availability of active, selective and stable catalyst for bioethanol steam reforming is a key point for the development of processes suitable to this purpose. In this work, the performance of different supported catalysts in the steam reforming of bioethanol at molten carbonate fuel cell (MCFC) operative condition has been focused and a decreasing activity has been related to the formation of carbon. Furthermore catalytic behaviour of a Ni supported catalyst has been tested under reforming condition both distillation industry’s waste and ethanol-water mixture. Results revealed that, superior alcohols (fusel oil) arising from the distillation process influence carbon formation and the presence of oxygen (ATR condition) preserves the catalyst activity which otherwise significantly deactivate mainly due to the carbon formation.

scholarly journals Effect of nickel loading on the activity of Ni/ZrO2 for methane steam reforming at low temperature

2009 ◽  
Vol 96 (1) ◽  
pp. 185-186 ◽  
Author(s):  
Long Q. Nguyen ◽  
Leonila C. Abella ◽  
Susan M. Gallardo ◽  
Hirofumi Hinode
Keyword(s):  
Low Temperature ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Methane Steam

Hierarchical Multiscale Modeling of Methane Steam Reforming Reactions

2011 ◽  
Vol 50 (5) ◽  
pp. 2600-2612 ◽  
Author(s):  
De Chen ◽  
Rune Lødeng ◽  
Hallvard Svendsen ◽  
Anders Holmen
Keyword(s):  
Multiscale Modeling ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Methane Steam ◽  
Hierarchical Multiscale ◽  
Reforming Reactions
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