Effects of support and promoter on Ru catalyst activity in microwave-assisted ammonia synthesis

Wang, Yuxin; Wildfire, Christina; Khan, Tuhin Suvra; Shekhawat, Dushyant; Hu, Jianli; Tavadze, Pedram; Quiñones-Fernández, Rosalynn; Moreno, Sara

doi:10.1016/j.cej.2021.130546

Cited by 11 publications

(31 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…20 This group has developed a Ru catalyst that has been enhanced by support- and promoter-effects. 23 Particularly, Cs was incorporated as a promoter for its electron-donating ability, 31 and microkinetic modelling found that Cs was the optimal promoter in maximally reducing the free energy of N 2 cleavage (the rate-limiting step of the reaction). 20 CeO 2 was used as a support material for its reversible Ce 3+ /Ce 4+ transformation and its abundance of oxygen vacancies, both of which enhance Ru surface electron density and promote conversion to NH 3 .…”

Section: Resultsmentioning

confidence: 99%

“…32 A composition of 2 wt% Cs and 4 wt% Ru supported on CeO 2 experimentally exhibits optimal activity in a microwave field, and full characterization of this catalyst composition has been reported in previous work by this group. 23 This CsRu2–4%/CeO 2 catalyst will be the catalyst used for the entirety of this paper. Scanning electron microscope (SEM) imaging of this catalyst (Fig.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Developing a microwave-driven reactor for ammonia synthesis: insights into the unique challenges of microwave catalysis

Melkote¹,

Muley

Dutta

et al. 2023

Catal. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Developing a microwave-driven reactor for ammonia synthesis: insights into the unique challenges of microwave catalysis

Melkote¹,

Muley

Dutta

et al. 2023

Catal. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…As mentioned previously, the existing catalysts can be heated using microwave irradiation. In the case of ruthenium-based catalysts, some production rates were reported to be from several hundred (400 °C, ambient pressure) to 4200 μmol g –1 h –1 at best (320 °C, 0.65 MPa), , while, in the case of plasma-catalytic ammonia synthesis using Ni on SiO 2 , synthesis rates as high as 6600 μmol g –1 h –1 (155 °C, ambient pressure) at best were reported; however, low-temperature plasma-mediated synthesis is still an emerging technology with inferior results, on average. Its main advantage remains the possibility of lower operating temperatures …”

Section: Comparison Of Methods For Ammonia Synthesis and Decompositionmentioning

confidence: 99%

Electrification of Catalytic Ammonia Production and Decomposition Reactions: From Resistance, Induction, and Dielectric Reactor Heating to Electrolysis

Ponikvar

Likozar

Gyergyek

2022

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

The conventional method for synthesizing ammonia is a power-hungry process that requires high operating temperatures (400–500 °C) in addition to elevated pressures (150–300 bar). The reaction is normally catalyzed by magnetite-based particles, and occurs between a single mole of nitrogen and three moles of hydrogen to form two moles of ammonia. The original Haber–Bosch process was developed and patented in 1916 by Fritz Haber and Carl Bosch. Since then, it has been extensively upgraded and optimized, with many improvements in the area of catalysis. Iron- and ruthenium-based catalysts are commonly used, where the active metal is deposited onto an appropriate support material. However, this method remains rather costly for the mass production of ammonia. The pursuit of a high-efficiency production process combined with the desirable use of renewables has driven the development of alternative, stand-alone methods (such as electrolysis, plasma- and microwave-mediated synthesis, various photochemical pathways, and catalysis aided by magnetic heating) as well as completely separate reactant-production procedures coupled with the traditional Haber–Bosch reactors. This review aims to highlight and critically evaluate recent developments in the electrification of ammonia production and decomposition.

show abstract

“…[40][41][42][43][44] In addition to this, CeO 2 has a very well-known ability to store oxygen [45] and reduce coke formation by altering the structural and electronic properties of catalysts. [41][42]46] The carbonaceous species that are deposited on the catalyst surface react with the surface oxygen from cerium oxide, and the gaseous oxidants in the reaction system then reoxidize it. In addition to this, CeO 2 as a support takes part during the catalysis in the oxidation reactions.…”

Section: Introductionmentioning

confidence: 99%

“…However, CeO 2 possesses many properties including high thermal stability, good redox behavior and high coke‐resisting abilities [40–44] . In addition to this, CeO 2 has a very well‐known ability to store oxygen [45] and reduce coke formation by altering the structural and electronic properties of catalysts [41–42,46] . The carbonaceous species that are deposited on the catalyst surface react with the surface oxygen from cerium oxide, and the gaseous oxidants in the reaction system then reoxidize it.…”

Section: Introductionmentioning

confidence: 99%

Improving the Coke Resistance of Ni‐Ceria Catalysts for Partial Oxidation of Methane to Syngas: Experimental and Computational Study

Khurana

Dahiya

Negi

et al. 2023

Chemistry An Asian Journal

View full text Add to dashboard Cite

The synthesis of syngas (H 2 : CO = 2) via catalytic partial oxidation of methane (CPOM) is studied over noble metal doped NiÀ CeO 2 bimetallic catalysts for CPOM reaction. The catalysts were synthesized via a controlled deposition approach and were characterized using XRD, BET-surface area analysis, H 2 -TPR, TEM, Raman and TGA analysis. The catalysts were experimentally and computationally studied for their activity, selectivity, and long-term stability. Although the pure 5Ni/CeO2 catalyst showed high initial activity (~90%) of CH 4 conversion, it rapidly deactivates around 20% of its initial activity within 140 hours of TOS. Doping of Ni/CeO 2 catalyst with noble metal was found to be coke resistant with the best-performing NiÀ Pt/CeO 2 catalyst showed ~95% methane conversion with > 90% selectivity at a temperature of 800 °C, having exceptional stability for about 300 hours of time-on-stream (TOS). DFT studies were performed to calculate the activation barrier for the CÀ H activation of methane over the Ni, Ni 3 Pt, Ni 3 Pd, and Ni 3 Ru (111) surfaces showed nearly equal activation energy over all the studied surfaces. DFT studies showed high coke formation tendency of the pure Ni (111) having a very small CÀ C coupling activation barrier (14.2 kJ/ mol). In contrast, the Ni 3 Pt, Ni 3 Pd, and Ni 3 Ru (111) surfaces show appreciably higher CÀ C coupling activation barrier (7 0 kJ/mol) and hence are more resistant against coke formation as observed in the experiments. The combined experimental and DFT study showed NiÀ Pt/CeO 2 as a promising CPOM catalyst for producing syngas with high conversion, selectivity and long-term stability suited for future industrial applications.

show abstract

Effects of support and promoter on Ru catalyst activity in microwave-assisted ammonia synthesis

Cited by 11 publications

References 47 publications

Developing a microwave-driven reactor for ammonia synthesis: insights into the unique challenges of microwave catalysis

Developing a microwave-driven reactor for ammonia synthesis: insights into the unique challenges of microwave catalysis

Electrification of Catalytic Ammonia Production and Decomposition Reactions: From Resistance, Induction, and Dielectric Reactor Heating to Electrolysis

Improving the Coke Resistance of Ni‐Ceria Catalysts for Partial Oxidation of Methane to Syngas: Experimental and Computational Study

Contact Info

Product

Resources

About