H2 Production from Catalytic Methane Decomposition Using Fe/x-ZrO2 and Fe-Ni/(x-ZrO2) (x = 0, La2O3, WO3) Catalysts

Abstract

An environmentally-benign way of producing hydrogen is methane decomposition. This study focused on methane decomposition using Fe and Fe-Ni catalysts, which were dispersed over different supports by the wet-impregnation method. We observed the effect of modifying ZrO2 with La2O3 and WO3 in terms of H2 yield and carbon deposits. The modification led to a higher H2 yield in all cases and WO3-modified support gave the highest yield of about 90% and was stable throughout the reaction period. The reaction conditions were at 1 atm, 800 °C, and 4000 mL(hgcat)−1 space velocity. Adding Ni to Fe/x-ZrO2 gave a higher H2 yield and stability for ZrO2 and La2O3 + ZrO2-supported catalysts whose prior performances and stabilities were very poor. Catalyst samples were analyzed by characterization techniques like X-ray diffraction (XRD), nitrogen physisorption, temperature-programmed reduction (TPR), thermo-gravimetric analysis (TGA), and Raman spectroscopy. The phases of iron and the supports were identified using XRD while the BET revealed a significant decrease in the specific surface areas of fresh catalysts relative to supports. A progressive change in Fe’s oxidation state from Fe3+ to Fe0 was observed from the H2-TPR results. The carbon deposits on Fe/ZrO2 and Fe/La2O3 + ZrO2 are mainly amorphous, while Fe/WO3 + ZrO2 and Fe-Ni/x-ZrO2 are characterized by graphitic carbon.

Sr Promoted Ni/W–Zr Catalysts for Highly Efficient CO2 Methanation: Unveiling the Role of Surface Basicity

“…One of the key advantages is the ability to stabilize the desired tetragonal t-ZrO 2 structure, , which is important for maintaining the structural integrity of the catalyst. By incorporating WO 3 , the aggregation and sintering of the support material can be effectively prevented . This leads to improved metal dispersion, ensuring a higher number of active sites available for the catalytic reaction.…”

“…The enhanced metal dispersion contributes to better catalytic performance, facilitating the interaction between the active metal species and the reactants, promoting the desired chemical transformations. Additionally, the presence of WO 3 in the catalyst support enhances the chemical and thermal stability of the catalyst system . This stability is crucial for maintaining the catalytic activity over extended periods of operation. − Thus, the use of tungstated zirconia proved to be highly active in several applications, such as methane decomposition, isomerization, CO 2 hydrogenation to methanol, and hydrogenolysis of glycerol. , …”

Combined Steam and CO2 Reforming of Methane over the Hierarchical Ni-ZrO2 Nanosheets/Al2O3 Catalysts at Ultralow Temperature and under Low Steam

“…From several literature studies over recent decades, Ni-based catalysts have been widely studied in the CSCRM process owing to their availability, the catalytic activity for CH 4 , and the cost effectiveness. − It was found that the CSCRM process is an extremely endothermic reaction requiring high operating temperature (700 to 900 °C), which then caused the catalyst deactivation by the metal sintering and coke deposition simultaneously. Coke majorly formed via the Boudouard reaction (eq ) and CH 4 decomposition (eq ).…”

Ni@4H-chromene-based core–shell nanoparticles: highly sensitive and selective chemosensors for the radiosensitizer bromodeoxyuridine

“…One of the most used applications is their title role in the fabrication of carbon nanotubes (CNTs). 13 They also find environmental applications in the field of the adsorption of hazardous dyes and inorganic pollutants, and thus they play a vital role in keeping the environment clean. NiNPs correspondingly show cytotoxicity against cancerous cells, as demonstrated by Chen et al , through coating NiNPs with the anti-cancer drug verbascoside (VB), which showed the facilitated uptake of the drug by K562 cells in the presence of NiNPs.…”