Study on Surface Pre-Treatment of FeCrAl Metallic Substrate for Hydrogen Production Catalysts

2013 ◽  
Vol 813 ◽  
pp. 465-470
Author(s):  
Xiao Xiao Zhang ◽  
Kun Su ◽  
Fan Lin Zeng ◽  
Yu Wen Zhang ◽  
Qi Fei Zhang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Supported Catalysts ◽  
Element Composition ◽  
Metallic Substrate ◽  
Air Atmosphere ◽  
Fecral Alloy ◽  
Film Adhesion ◽  
Metal Support ◽  
Active Coating ◽  
Pre Treatment

Metal supported catalysts in hydrogen production reactor has a very broad application prospect. However, the film adhesion of active coating with the metal support is the key problem which needed to be solved urgently. In this paper, FeCrAl alloy was chosen as the metallic substrate. The effects of oxidation temperature and time on the morphology, crystal phase and element composition of the metal surface were investigated by XRD, SEM and EDAX. The results show that after pre-treatment of FeCrAl Metallic Substrate,a dense transition layer of α-Al2O3 formed on the surface of the metallic support. Thus the oxidized α-Al2O3 layer and the γ-Al2O3 coating could combine together better. The optimum pre-treatment condition is at 950°C for 10h in air atmosphere.

scholarly journals Hydrogen Photo-Production from Glycerol Using Nickel-Doped TiO2 Catalysts: Effect of Catalyst Pre-Treatment

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3351 ◽  
Author(s):  
Jesús Hidalgo-Carrillo ◽  
Juan Martín-Gómez ◽  
Julia Morales ◽  
Juan Carlos Espejo ◽  
Francisco José Urbano ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Uv Light ◽  
Irradiation Time ◽  
Fold Increase ◽  
Synthetic Methods ◽  
Solar Irradiation ◽  
Catalyst Pretreatment ◽  
Metal Support ◽  
Pre Treatment ◽  
Nickel Species

In the present piece of research, hydrogen production via the photo-reforming of glycerol (a byproduct from biodiesel generation) is studied. Catalysts consisted of titania modified by Ni (0.5% by weight) obtained through deposition–precipitation or impregnation synthetic methods (labelled as Ni-0.5-DP and Ni-0.5-IMP, respectively). Reactions were performed both under UV and solar irradiation. Activity significantly improved in the presence of Ni, especially under solar irradiation. Moreover, pre-reduced solids exhibited higher catalytic activities than untreated solids, despite the “in-situ” reduction of nickel species and the elimination of surface chlorides under reaction conditions (as evidenced by XPS). It is possible that the catalyst pretreatment at 400 °C under hydrogen resulted in some strong metal–support interactions. In summary, the highest hydrogen production value (ca. 2600 micromole H2·g−1) was achieved with pre-reduced Ni-0.5-DP solid using UV light for an irradiation time of 6 h. This value represents a 15.7-fold increase as compared to Evonik P25.

Co-processing of hydrodeoxygenation and hydrodesulfurization of phenol and dibenzothiophene with NiMo/Al2O3–ZrO2 and NiMo/TiO2–ZrO2 catalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jesús Andrés Tavizón Pozos ◽  
Gerardo Chávez Esquivel ◽  
Ignacio Cervantes Arista ◽  
José Antonio de los Reyes Heredia ◽  
Víctor Alejandro Suárez Toriello
Keyword(s):  
Active Sites ◽  
Reaction Rate ◽  
Supported Catalysts ◽  
Initial Reaction Rate ◽  
Initial Reaction ◽  
Competition Effect ◽  
Support Interaction ◽  
Highly Active ◽  
Metal Support Interaction ◽  
Metal Support

Abstract The influence of Al2O3–ZrO2 and TiO2–ZrO2 supports on NiMo-supported catalysts at a different sulfur concentration in a model hydrodeoxygenation (HDO)-hydrodesulfurization (HDS) co-processing reaction has been studied in this work. A competition effect between phenol and dibenzothiophene (DBT) for active sites was evidenced. The competence for the active sites between phenol and DBT was measured by comparison of the initial reaction rate and selectivity at two sulfur concentrations (200 and 500 ppm S). NiMo/TiO2–ZrO2 was almost four-fold more active in phenol HDO co-processed with DBT than NiMo/Al2O3–ZrO2 catalyst. Consequently, more labile active sites are present on NiMo/TiO2–ZrO2 than in NiMo/Al2O3–ZrO2 confirmed by the decrease in co-processing competition for the active sites between phenol and DBT. DBT molecules react at hydrogenolysis sites (edge and rim) preferentially so that phenol reacts at hydrogenation sites (edge and edge). However, the hydrogenated capacity would be lost when the sulfur content was increased. In general, both catalysts showed similar functionalities but different degrees of competition according to the highly active NiMoS phase availability. TiO2–ZrO2 as the support provided weaker metal-support interaction than Al2O3–ZrO2, generating a larger fraction of easily reducible octahedrally coordinated Mo- and Ni-oxide species, causing that NiMo/TiO2–ZrO2 generated precursors of MoS2 crystallites with a longer length and stacking but with a higher degree of Ni-promotion than NiMo/Al2O3–ZrO2 catalyst.

Interface engineering of palladium and zinc oxide nanorods with strong metal–support interactions for enhanced hydrogen production from base-free formaldehyde solution

2019 ◽  
Vol 7 (15) ◽  
pp. 8855-8864 ◽  
Author(s):  
Leilei Du ◽  
Kaicheng Qian ◽  
Xiaohui Zhu ◽  
Xiaoqing Yan ◽  
Hisayoshi Kobayashi ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Catalytic Reactions ◽  
Zinc Oxide Nanorods ◽  
Formaldehyde Solution ◽  
Promising Strategy ◽  
Oxide Nanorods ◽  
Metal Support ◽  
Catalytic Hydrogen ◽  
Metal Support Interactions ◽  
Almost All

Catalytic hydrogen production from formaldehyde solution provides a promising strategy for future hydrogen-based energy systems, while almost all of the present catalytic reactions are carried out in highly alkaline medium.

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