What is desorption in TGA?
From Wikipedia, the free encyclopedia. Temperature programmed desorption (TPD) is the method of observing desorbed molecules from a surface when the surface temperature is increased.
What is adsorption and desorption isotherm?
Adsorption–desorption isotherm volume adsorbed obtained by measuring the amount of an inert gasesous or liquid substance (the ‘sorbent’, usually H2 or N2) which adsorbs onto the surface of interest (the ‘sorbate’), and the subsequent amount that desorbs at a constant temperature.
What is difference between adsorption and desorption?
The key difference between adsorption and desorption is that adsorption refers to the process by which some solids hold the molecules of a gas or liquid or solute as a thin film, whereas desorption refers to the release of an adsorbed substance from a surface.
How do you calculate desorption rate?
We compute the desorption rate using transition-state theory by taking the dividing-surface far from the surface of the solid.
What is NH3 TPD?
Temperature-programmed desorption (TPD) is widely used for characterization of heterogeneous catalysts. For zeolites and oxide surfaces, NH3-TPD is generally used to measure the amount of acid sites together with the acid strength [1, 2].
How does temperature programmed desorption work?
Temperature-programmed desorption (TPD) is used to evaluate the amount and types of oxygen-containing surface groups in carbon materials. The key principle is to heat material in an inert atmosphere and record spectra of exhaling gases (CO and CO2) by quadrupole mass spectrometry.
What do you mean by desorption?
Desorption is the physical process where a previously adsorbed substance is released from a surface. Desorption can occur after a reaction between a catalyst and an adsorbed compound; or during stripping or chromatography which are types of separation processes.
What is absorption BYJU’s?
In biology, absorption is the process where substances are assimilated (or absorbed) into the cells through osmosis or diffusion. In the human body, nutrients are absorbed from digestion and supplied to the rest of the body through the bloodstream. Read more by registering at BYJU’S NEET.
What is H2 TPD?
Hydrogen Temperature-Programmed Desorption (H2 TPD) of Supported Platinum Catalysts – ScienceDirect.