Surface Characterization, Common Laboratory

Surface Characterization, Common Laboratory

To establish the structure activity relationship between a catalyst and its activity in different gas phase or liquid phase reactions, a common laboratory provides different techniques to identify the structural properties of catalytic support or active catalysts.

Structural properties are influenced by many factors, including by the choice of the three major catalyst constituents: support, active component (metal, oxides) and promoters. Eventual catalytic activity depends on the interaction between the major catalyst constituents when exposed to different temperatures in the presence or absence of different gases and/or liquids.

Gas Adsorption

Supports and active catalyst properties such as surface area, pore size distribution and pore volume have a major influence on the eventual catalytic activity. To establish these properties, we have at our disposal an Accelerated Surface Area and Porosity Analyzer (ASAP 2420) from Micromeritics that is dedicated to physisorption, a gas adsorption analysis technique. ASAP 2420 allows for the determination of abovementioned properties by incremental addition of a non-reactive adsorptives (N2, Ar, Kr, CO2) at liquid nitrogen or argon temperatures to a previously degassed porous solid material.

Properties of active components of a catalyst (usually metal) are identified utilizing Accelerated Surface Area and Porosimetry Analyzer (ASAP 2020) from Micromeritics, which is dedicated to Chemisorption. This gas adsorption analysis technique allows determination of properties such as metal dispersion, metal surface area, heat of chemical adsorption, strong and weak chemisorption, and the crystallite size of a catalyst. These properties are accessed by high vacuum-high temperature pretreatment of a solid sample and measurement of the pressure above the sample when submitting to incremental gas (H2, CO) additions.

Thermal Analysis

During the preparation of support, active catalysts (as well as during the catalytic reaction)—these inorganic materials are exposed to different temperature profiles in the presence or absence of different gases or liquids. To establish the change of properties of inorganic materials when exposed to high temperatures, Thermal Analysis techniques such as Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) are utilized. Thermogravimetric Analysis (TGA) is used to study mass change of solids and liquids while exposed to variable temperature and gas environment. During TGA Analysis, a sample can be exposed to temperatures up to 1600 °C in the presence of inert (N2, Ar,…), oxidizing (Air, O2,..) as well as diluted hydrogen (4% H2 in for example Argon). Differential Scanning Calorimetry (DSC) is used to study properties such as thermal capacity, enthalpy and glass transition temperature can be accessed, differential heat of adsorption. Materials can be studied from -150 °C up to 500 °C under inert (N2, Ar..) or oxidizing (Air, O2,..) gases.

Dynamic Light Scattering (DLS) and Static Light Scattering (SLS)

Dynamic Light Scattering and Static Light Scattering techniques are utilized to determine the particle size distribution, zetapotential, point of zero charge, as well as molecular weight distribution. Malvern ZEN 3600 instruments measure particle size (hydrodynamic diameter) between 0.6 nm up to 6 μm, molecular weight in the range of 1000 to 2*107 Da and zetapotential for particles in the size range of 5 nm to 10μm. A Mastersizer 2000 that is solely dedicated to particle size analysis extends the measuring range from 0.02 μm up to 2000 μm.

Facilities

  • Thermogravimetric Analysis (TGA) Brand: Netzsch, Mettler Toledo,
    Model: STA 499 F1 Jupiter, TGA/DSC 1
    Thermogravimetric Analysis (TGA) Thermogravimetric Analysis (TGA) is used to study the response of different materials while exposed to variable temperature and gas environment. Temperatures up to 1600 °C can be reached. Reaction gasses that can be applied are inert (N2, Ar,..) and oxidizing gasses (Air, O2,..) as well as diluted hydrogen (4% H2 in for example Argon). Properties such as mass change and relatively large enthalpy changes can be measured.
  • Thermal Analysis by Thermogravimetric Analysis (TGA/DSC)  coupled with FTIR Brand: Mettler Toledo, Thermo Scientific,
    Model: TGA/DSC1, Nicolet iS10 and Nicolet iZ10
    Thermal Analysis by Thermogravimetric Analysis (TGA/DSC) coupled with FTIR Thermogravimetric Analysis (TGA) is used to study the response of different materials while exposed to variable temperature and gas environment. Temperatures up to 1100 °C can be reached. Reaction gasses that can be applied are inert (N2, Ar,..) and oxidizing gasses (Air, O2,..) as well as diluted hydrogen (4% H2 in for example Argon). Properties such as mass change and relatively large enthalpy changes can be measured. TGA instruments in our possession are actually Simultaneous Thermal Analysis (STA) instruments capable of measuring both TGA as well as Differential Scanning Calorimetry (DSC) signal.
  • Differential Scanning Calorimetry (DSC) Brand: Mettler Toledo,
    Model: DSC 1
    Differential Scanning Calorimetry (DSC) Differential Scanning Calorimetry (DSC) is used to study the response of different materials while exposed to variable temperature. Properties such as thermal capacity, enthalpy and glass transition temperature can be accessed. Materials can be studied from -150 °C up to 500 °C under inert (N2, Ar..) or oxidizing (Air, O2,..) gasses. Installed autosampler equipped with automatic pan lid removal and automatic pan piercing accelerates measurement of multiple samples (turntable can accommodate up to 34 sample pans).
  • Surface Area and Porosity Analyser – Chemisorption Brand: Micromeritics Instrument Corporation,
    Model: ASAP 2020
    Surface Area and Porosity Analyser – Chemisorption Surface Area and Porosity Analyser dedicated to Chemisorption is an adsorption analysis technique that allows determination of properties such as metal dispersion, metal surface area, heat of chemical adsorption, strong and weak chemisorption, crystallite size of a catalyst. These properties are accessed by high vacuum pretreatment of solid sample and measurement of the pressure above the sample when submitting to incremental gas (H2, CO..) additions. ASAP 2020 consist of two independent vacuum systems that allow simultaneous preparation of two samples and analysis of another.
  • Surface Area and Porosity Analyser – Physisorption Brand: Micromeritics Instrument Corporation,
    Model: ASAP 2420
    Surface Area and Porosity Analyser – Physisorption Surface Area and Porosity Analyser dedicated to Physisorption is an adsorption analysis technique that allows determination of surface area, pore volume and pore size distribution by incremental addition of an non-reactive adsorptives (N2, Ar, Kr, CO2) at liquid nitrogen or argon temperatures to a previously degassed porous solid material. ASAP 2420 consist of two independent instruments: one to degas the samples and other to analyze the samples. Degas system can independently degas 12 samples, samples may be added or removed from degas ports with a minimum disturbance to other samples. Maximum degas temperature is 450 °C.
  • Zeta Sizer Nano Series, Mastersizer 2000 Brand: Malvern,
    Model: ZEN3600, APA2000
    Zeta Sizer Nano Series, Mastersizer 2000 Dynamic Light Scattering and Static Light Scattering techniques preformed by ZEN 3600 instruments utilize “red” laser of 632.8 nm wavelength of 4 mW strength to obtain particle size distribution, zetapotential, point of zero charge as well as molecular weight distribution. Particle size (hydrodynamic diameter) between 0.6 nm up to 6 μm can be measured, molecular weight in the range of 1000 to 2*107 Da (with a minimum volume of 12 μL) and zetapotential for particles in the size range of 5 nm to 10μm (minimum sample volume 150 μL).