Catalyst Degradation
Catalyst Degradation - Related Videos
11:15
HKUST-1 as a Heterogeneous Catalyst for the Synthesis of Vanillin
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Cited by 12 •
2016
The conversion of trans-ferulic acid to vanillin was achieved by heterogeneous catalysis. HKUST-1 was employed in this synthesis and the essential step in the catalytic process was the generation of unsaturated metal sites. Thus, when the catalyst was activated under vacuum, full vanillin conversion (yield of 95%) was obtained.
09:53
Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture
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Cited by 3 •
2018
Here we present a protocol to measure the modulus of rupture of an extruded catalyst and the breakage of said catalyst extrudates by collision against a surface or by compression in a fixed bed.
10:38
Electrochemical Measurements of Supported Catalysts Using a Potentiostat/Galvanostat
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2023
Source: Laboratory of Dr. Yuriy Román — Massachusetts Institute of Technology A potentiostat/galvanostat (often referred to as simply a potentiostat) is an instrument that measures current at an applied potential (potentiostatic operation) or measures potential at an applied current (galvanostatic operation) (Figure 1). It is the most commonly used instrument in the electrochemical characterization of anode and cathode materials for fuel cells, electrolyzers, batteries, and supercapacitors.
02:58
Regulated Protein Degradation
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2020
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells. Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
02:11
Proteins: From Genes to Degradation
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2020
Within a biological system, the DNA encodes the RNA, and the nucleotide sequence in the RNA further defines the amino acid sequence in the protein. This is referred to as “The Central Dogma of Molecular Biology” - a term coined by Francis Crick. Central dogma is a firm principle in biology that defines the flow of genetic information within any life form. The two fundamental steps in central dogma are - transcription and translation. Transcription is the synthesis of RNA molecules by RNA...
FAQs
Poisoning occurs when strongly adsorbed species occupy or alter active sites, directly preventing reactants from using them. Fouling instead covers the catalyst with deposits such as carbon, which can block access to the surface. Distinguishing these pathways helps researchers connect losses in activity or selectivity with the appropriate feed composition and choose a suitable regeneration strategy.
Elevated temperature can promote sintering, in which catalyst structure changes and active material becomes less favorably distributed for reaction. Heat can therefore reduce the number or accessibility of active sites even when no external poison is present. Evaluating temperature as a degradation variable supports reaction designs that balance chemical conversion with preservation of catalyst structure.
Unfavorable oxidation-reduction changes can modify the chemical state of the active material, changing how effectively it participates in the intended reaction. This pathway differs from simple site blocking because the catalyst itself may be altered chemically. Tracking operating conditions that promote these changes helps researchers identify deactivation routes and adjust reaction environments to improve durability.
Researchers should compare catalyst performance with temperature, feed composition, and operating history while considering whether activity, selectivity, or structural integrity has changed. These observations can point toward poisoning, carbon deposition, sintering, dissolution or leaching, or oxidation-reduction effects. Separating these possibilities is important because each pathway can require a different design or regeneration response.
A practical study compares catalytic activity, selectivity, and structural integrity over the course of operation, then relates observed losses to conditions such as temperature and feed composition. Researchers use this relationship to identify likely deactivation pathways rather than treating every performance decline as identical. The resulting diagnosis guides optimization of operating conditions and development of regeneration strategies.
Regeneration strategies are useful when performance loss results from a pathway that can be addressed by restoring active-site accessibility or reversing an unfavorable catalyst change. Their selection depends on the diagnosed cause, such as strongly adsorbed poisons, carbon deposits, heat-related structural changes, leaching, or redox effects. Studying regeneration can extend catalyst usefulness in industrial chemical operation.
Durable catalysts help maintain reaction activity and selectivity during continued operation, which is important in energy conversion, environmental remediation, and chemical manufacturing. Degradation studies reveal how feed composition and temperature influence useful lifetime. That knowledge supports catalyst designs and operating conditions that preserve performance rather than optimizing only the initial reaction rate.