Benefits

• Quickly and accurately determine both physical adsorption (quantity of adsorbed or desorbed molecules)  and chemisorption measurements in a low-cost and upgradeable system.
•  Dual ports, built-in sample cell cooling fan, four carrier gas inlets, a preparation gas inlet, and the optional capability to accommodate a mass spectrometer or other external detector. 
• Optional ChemiSoft™ TPx System (temperature-programmed controller and software) expands the capability of the ChemiSorb 2720 or 2750 to include: multipoint BET surface area, temperature-programmed reactions, data archiving, and advanced data reduction and reporting options.

Applications

Catalysts

The active surface area and pore structure of catalysts have great influence on reaction rates and yield of product. Limiting the pore size allows only molecules of
desired sizes to enter and leave; creating a selective catalyst that will produce primarily the desired product. Chemisorption experiments are valuable for the selection of catalysts for a particular purpose, qualification of catalyst vendors, and the testing of a catalyst’s performance over time to establish when the catalyst should be reactivated or replaced.

Fuel Cells

Platinum-based catalysts including Pt/C, PtRu/C, and PtRuIr/C may be characterised by temperature-programmed reduction to determine the number of oxide phases or by pulse chemisorption to characterise the metal surface area, metal dispersion, and average crystallite size.

Partial oxidation

Manganese, cobalt, bismuth, iron, copper, and silver oxides are often used for the gas-phase oxidation of ammonia, methane, ethylene, propylene, etc. Temperature-programmed oxidation and temperature-programmed desorption may be used to measure the heat of desorption of oxygen from these catalysts and the heat of dissociation of oxygen from the metal oxide.

Catalytic cracking

Catalytic processes are used extensively for refining petroleum. Acid catalysts such as zeolites are used for catalytic cracking and are often characterized using ammonia chemisorption and temperature-programmed desorption for determining the number and strength of the acid sites.

Catalytic-reforming catalysts containing platinum, rhenium, tin on silica, alumina, or silica-alumina are used for the production of hydrogen, aromatics, and olefins. These catalysts are often  characterised using pulse chemisorption techniques to determine the number of active sites, the percent metal dispersion, and average crystallite size.

Isomerization catalysts such as smallpore zeolites (mordenite and ZSM-5) containing noble metals (typically platinum) are used to convert linear paraffins to branched paraffins and thus increase the octane number and value for blending gasoline. Temperature-programmed reduction and pulse chemisorption are often combined to characterise these catalysts.

Hydrocracking, hydrodesulfurization,and hydrodenitrogenation catalysts are typically composed of metal sulfides (nickel, tungsten, cobalt, and molybdenum). Hydrocracking catalysts are used for processing feeds containing polycyclic aromatics that are unsuitable for typical catalytic cracking processes. The hydrocracking process is used for upgrading these low-value products to gasoline and diesel fuel. Hydrodesulfurization and hydrodenitrogenation are used for removing sulfur and nitrogen, respectively, from petroleum feeds. Both sulfur and nitrogen are catalytic poisons and also are the source of pollution (acid rain) if they are not removed from gasoline and diesel fuel.Temperature-programmed reduction and oxygen chemisorption are used to characterize the oxide phases and active surface area of these materials.

Fischer-Tropsch synthesis uses cobalt and iron-based catalysts to convert syngas (carbon monoxide and hydrogen) to hydrocarbons larger than methane. The Fischer-Tropsch processes are of great importance as they provide hydrocarbons that are rich in hydrogen and do not contain sulfur or nitrogen. These hydrocarbons are a potential liquid fuel that is easily transported and distributed, and can then be reformed to hydrogen to supply fuel cells. These catalysts are often characterised by pulse chemisorption and temperature-programmed desorption to determine the metal  surface area and the average size of the metal crystallites.

Accessories

Added Capability – Optional ChemiSoft TPx System

• Optional ChemiSoft TPx System (temperature-programmed controller and software) expands the capabilities of the ChemiSorb 2720 and 2750 to include temperature-programmed reactions, data archiving, and advanced data reduction and reporting options
• Expanded physisorption capability includes multipoint BET surface area.