Chemisorption

Chemisorption For Catalysts Characterisation

Chemisorption is a specific type of adsorption characterised by a strong interaction between the adsorbate (this could be any gas that adsorbs on to the surface of the material) and the surface of the material (adsorbent).
In physisorption weak Van der Waals forces attract the adsorbate to the adsorbent while in chemisorption these bonds are ionic or covalent, depending on the nature of the material.
Characteristics of chemisorption include:

formation of strong chemical bond between adsorbate and chemically active surface sites
often have a high activation energy
generally irreversible except at high temperatures
due to the high adsorption energy the assumption of monolayer adsorption works well, although some multilayer adsorption or spillover is possible

Chemisorption is widely used in catalysts characterisation for investigating:

active metal surface area, particularly in heterogeneous catalysis where transition metals are used
characterisation of metal dispersion
acid site distribution
crystallite size
heats of adsorption
adsorption kinetics

Related technologies such as Temperature programmed Reduction (TPR), temperature programmed desorption (TPD) and temperature programmed oxidation (TPO) can be used to gain further information about both chemisorption and physisorption processes.

Review recent papers citing use of Quantachrome chemisorption scientific instruments:

TITLE: Facile Synthesis of Mesoporous Cu2O Microspheres with Improved Catalytic Property for Dimethyldichlorosilane Synthesis
AUTHORS: Zailei Zhang, Hongwei Che, Yingli Wang et al - Chinese Academy of Sciences, China
INSTRUMENT: CHEMBET PULSAR
USAGE: Temperature programmed reduction (TPR) measurements were carried out on Automated chemisorption analyzer
View paper

TITLE: Controlled synthesis of highly dispersed semi-embedded ruthenium nanoparticles in porous carbon framework with more exposed active sites
AUTHORS:Ying Li, Guojun Lan, Haiyan Wang et al - Zhejiang University of Technology, China
INSTRUMENT: Autosorb-1C
USAGE: The dispersion of Ru was obtained by CO chemisorption method, which was carried out at 40 °C
View paper

More chemisorption research papers

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Find out more about our range of chemisorption scientific equipment:
Autosorb-iQ-C
ChemBET TPR/TPD
ChemBET PULSAR TPR/TPD