Microcantilever-Based In Situ Temperature-Programmed Desorption (TPD) Technique

Temperature-programmed desorption (TPD) is an essential technique for characterizing the fundamental properties of advanced catalysts like catalytic activity and kinetics. However, the available TPD instruments are bulky and use ex situ detectors to measure the probe molecules in the elution gas flow. Herein, we demonstrate an in situ TPD technique by developing a silicon microcantilever that integrates functional elements for mass measuring and programmable sample heating. An only nanogram-level sample is required to load on the microcantilever free end, where the integrated microheater provides programmed temperatures and the desorption-induced mass change can be measured in situ. In situ TPD can continuously measure the number of desorbed molecules from the catalyst during programmed heating, without the need for ex situ detectors. With a single-time in situ TPD measurement, the desorption activation energy can be directly calculated. The proposed in situ TPD method outperforms the existing TPD techniques and is expected to enable next-generation TPD applications.