Temperature programmed reduction (TPR) is a material characterization process commonly used in catalysis characterization and screening to examine the surface chemistry of metals and metal oxides under varying thermal conditions. TPR-enabled mass spectrometry equipment can acquire quantitative and qualitative data relating to the reducing gas mixtures that flow across and interact with metallic samples. This process is integral to catalyst investigation as it provides precise details on catalyst reducibility and reaction rates in the presence of metal surfaces. Taken together, this information guides the user on catalyst reproducibility and supports quality control of existing catalytic substances by setting benchmarks or reduction profiles that manufactured catalysts should maintain.
How is TPR Performed?
In a typical TPR experiment, a metal oxide such as nickel (NiO) is dispersed upon a surface and tested in a system known as a fixed bed reactor. A reducing gaseous mixture such as hydrogen (H2) is then flowed across the catalyst under gradually increasing thermal conditions. This linear heating allows reduction rate to be correlated with temperature. A highly-sensitive detector continually analyzes the chemical difference in atmospheric concentration at the outlet, producing an accurate picture of the maximum or peak reduction rate of the catalyst. TPR profiles produced using this technique are instrumental in ascertaining a metal oxide’s potential use as a commercial or industrial catalytic material.
Physiochemical catalytic data cannot be acquired using TPR methods alone, however, which is why linear heating experiments of this methodology are typically used in conjunction with spectrometric equipment.
TPR Mass Spectrometers
TPR-enabled mass spectrometers combine a microreactor chamber and a mass spectrometer system for a selection of data acquisition modes from catalytic reaction experiments. For example, the integrated CATLAB-PCS system includes a wide range of operating configurations that enable multiple experimental methods for catalysis and reaction studies.
The Hiden Analytical CATLAB-PCS system features a sensitive thermocouple in the reactor bed for direct catalyst temperature measurement alongside the linear heating and reduction values gathered by the system’s intuitive software, all integrated with data acquisition from the mass spectrometer. It has template-driven software, allowing for precise and automated control of gas composition and flow rates. The standard system can be manually operated or programmed to established templates, with heating rates of up to 1000 °C in increments of 1 – 20 °C/min.
With full control of all the mass spectrometer parameters and reactor heating rates, the CATLAB-PCS provides for comprehensive analysis in modern catalysis studies.
TPR Experiments with Hiden Analytical
Hiden Analytical has over 35 years’ experience in the design, manufacture, and supply of quadrupole mass spectrometers. Featuring application specific configurations and exceptional modular designs, our products set the bench mark for laboratory instrumentation.
We offer a broad range of mass spectrometers for TPR studies, with additional modules for the acquisition of data unique to specific areas of research. If you would like to learn more about our TPR mass spectrometers, please do not hesitate to contact us.