Differences between chemisorption and physisorption

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Differences between chemisorption and physisorption
Differences between chemisorption and physisorption Image source : https://psiberg.com/physisorption-vs-chemisorption/

Physical adsorption, also known as physisorption, is a reversible phenomenon involving weak Van der Waals forces between adsorbate and adsorbent, whereas chemisorption is an irreversible phenomenon involving strong chemical interaction between adsorbate and adsorbent.

S.NPhysisorptionChemisorption
1.It is a reversible phenomenon.It is an irreversible phenomenon.
2.Physisorption is caused by Van der Waals forces.It is caused by chemical bond formation.
3.It is not specific in nature.It is highly specific in nature.
4.Low temperature favors the physisorption process. It decreases as the temperature rises.High temperature is favorable for adsorption. It increases as the temperature rises.
5. Easily liquefiable gases are readily adsorbed.Gases that can react
with the adsorbent show
chemisorption
6.Enthalpy of adsorption is low (20–
40 kJ mol-1).		The enthalpy of chemisorption is high (80-240 kJ mol-1).
7.Physical adsorption has a lower activation energy.Chemical adsorption has a higher activation energy.
8.Physisorption is a weak phenomenon.It is a strong process.
9.It is a multi-layered process.This type of adsorption is almost entirely a single-layered phenomenon.
10.For example: Adsorption of oxygen or hydrogen on the surface of charcoalFor example: Adsorption of oxygen on metal surfaces.

References

  1. Hiemenz P. C. & Rajagopalan R. (1997). Principles of colloid and surface chemistry (3rd ed. rev. and expanded Paul C. Hiemenz Raj Rajagopalan). Marcel Dekker.
  2. https://nitsri.ac.in/Department/Chemical%20Engineering/Adsorption.pdf
  3. https://www.embibe.com/exams/application-of-adsorption/
  4. https://byjus.com/jee/adsorption/
  5. https://nitsri.ac.in/Department/Chemical%20Engineering/Adsorption.pdf

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Kabita Sharma

Kabita Sharma is a Ph.D. student in the Department of Chemistry at the University of North Texas, USA. Her research focuses on understanding protein degradation mediated by PROTAC (Proteolysis-Targeting Chimera) molecules and on exploring their potential for targeted protein degradation to treat diseases such as cancer. Through this work, she aims to advance drug discovery by targeting previously inaccessible or undruggable sites where PROTAC molecules can operate effectively. Additionally, she is analyzing how the buried surface area of proteins affects their binding and unbinding affinities. Using computational tools, she explores the challenges of removing one infected protein from another during treatment. Driven by a passion for solving complex scientific challenges, Kabita uses her knowledge in chemistry, chemical biology, and computational tools to advance her research. Beyond her academic pursuits, she aspires to inspire others toward science and its wonders through writing and sharing her knowledge.

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