Special Issue on Catalyst Deactivation and Regeneration

Castaño, Pedro

doi:10.3390/catal11070798

Cited by 3 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the adsorption of certain toxic substances on the active center can lead to catalyst damage. There are several factors responsible for catalyst deactivation, including poisoning, carbon build-up, sintering, loss of active components, and changes in carrier morphology . This study presents an initial exploration of catalyst deactivation, drawing upon experimental data and characterization outcomes.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al₂O₃-Catalyzed Deactivation and Regeneration

Li,

Cheng,

Zhang

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Benzimidazole compounds are a pivotal structure within various pharmaceuticals and possess significant medical value. Utilizing Cu−Pd/γ-Al 2 O 3 as the catalyst, benzimidazole can be synthesized directly from 2-nitroaniline and ethanol, offering advantages such as readily available starting materials, high efficiency, and a straightforward process. Modification of the Cu−Pd/γ-Al 2 O 3 catalyst with potassium (K) can significantly enhance its catalytic activity. The introduction of K into the Cu− Pd/γ-Al 2 O 3 catalyst effectively sustains and promotes the formation of active sites within the CuPd alloy. Furthermore, K facilitates the dehydrogenation of alcohols, thereby expediting the overall coupling reaction rate. The impact of various factors such as space velocity, reaction temperature, reaction pressure, and solvent on the catalyst's performance was investigated during the continuous flow synthesis of benzimidazole from ethanol and orthonitroaniline. Additionally, characterization techniques such as Nitrogen gas adsorption/desorption, TEM, TPD, TPO, XRD, and TG were employed to explore the catalyst deactivation mechanism. The research outcomes demonstrate that the 5 wt %Cu−5 wt %Pd/ γ-Al 2 O 3 catalyst modified with K exhibited excellent catalytic performance, achieving complete conversion of ortho-nitroaniline and impressive 98.2% selectivity toward 2-methylbenzimidazole under the conditions of a reaction temperature of 433 K, a pressure of 5 MPa, a mass space velocity of 0.28 h −1 , and a water-to-ethanol volume ratio of 1:3. Nevertheless, catalyst deactivation became evident after 42 h of continuous operation. Analysis revealed that catalyst deactivation was attributed to changes in the carrier's crystalline phase, catalyst coking, and trace amounts of CO poisoning. The deactivated catalyst could be effectively regained through high-temperature calcination and reduction. The findings of this study provide a straightforward method for regenerating efficient catalysts within the "alcohol dehydrogenation-hydrogen transfer-hydrogenation" coupled reaction system.

show abstract

Section: Resultsmentioning

confidence: 99%

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al₂O₃-Catalyzed Deactivation and Regeneration

Li,

Cheng,

Zhang

et al. 2023

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…In addition, it is the most important deactivation mechanism for catalysts used for the hydrotreating of middle distillates. Other types of deactivation are caused by the deposition of metals (metal sintering), thermal degradation, or segregation of the active phase [6,8,[10][11][12]. The catalyst may be poisoned by the contaminants in the feedstock.…”

Section: Introductionmentioning

confidence: 99%

Comparison of the Accelerated and Spontaneous Deactivation of the HDS Catalyst

Jaklová¹,

Šindelářová²,

Kohout³

et al. 2021

Processes

View full text Add to dashboard Cite

Owing to the increased use of secondary materials for diesel production, refineries must confront bad quality parameters. Therefore, catalysts with certain capabilities (to remove heteroatoms and improve quality parameters at low hydrogen consumption) and their lifetimes are required. An important parameter that influences the quality of the products and the economy of the unit is the activity of the catalyst. Prior to industrial use, the catalyst is typically tested in a pilot unit. This is necessary to obtain a considerable amount of data on the lifetime of the catalyst in the shortest feasible time. Here, deactivation steps were used to test the catalyst. Two experiments were performed to evaluate the effect of two types of accelerated deactivations on the catalyst activity and product properties. The first type of deactivation proceeded for 6 h and comprised a tripling of the amount of incoming feedstock, and the second type proceeded for 18 h without an increase in the amount of feedstock. For both cases, the pressure and hydrogen flow were minimised. Both types of accelerated deactivations had similar effects on the quality of the final products and catalyst. The only difference was in the duration of catalyst recovery after deactivation. The results were compared with those of a test in which the spontaneous deactivation of the catalyst was studied.

show abstract

Characterization, catalytic, and recyclability studies of nano-sized spherical palladium particles synthesized using aqueous poly-extract (turmeric, neem, and tulasi)

Velidandi

Sarvepalli

Gandam

et al. 2023

Environmental Research

View full text Add to dashboard Cite

Special Issue on Catalyst Deactivation and Regeneration

Abstract: Catalyst deactivation causes major losses in the chemical industry worldwide every year [...]

Cited by 3 publications

References 5 publications

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al₂O₃-Catalyzed Deactivation and Regeneration

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al₂O₃-Catalyzed Deactivation and Regeneration

Comparison of the Accelerated and Spontaneous Deactivation of the HDS Catalyst

Characterization, catalytic, and recyclability studies of nano-sized spherical palladium particles synthesized using aqueous poly-extract (turmeric, neem, and tulasi)

Contact Info

Product

Resources

About

Special Issue on Catalyst Deactivation and Regeneration

Abstract: Catalyst deactivation causes major losses in the chemical industry worldwide every year [...]

Cited by 3 publications

References 5 publications

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al2O3-Catalyzed Deactivation and Regeneration

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al2O3-Catalyzed Deactivation and Regeneration

Comparison of the Accelerated and Spontaneous Deactivation of the HDS Catalyst

Characterization, catalytic, and recyclability studies of nano-sized spherical palladium particles synthesized using aqueous poly-extract (turmeric, neem, and tulasi)

Contact Info

Product

Resources

About

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al₂O₃-Catalyzed Deactivation and Regeneration

Synthesis of 2-Methylbenzimidazole in Continuous Flow: Mechanism of Cu–Pd/(K)γ-Al₂O₃-Catalyzed Deactivation and Regeneration