Instrumental Analysis of Advanced Catalysts Based on Resonant Microcantilevers

Advanced catalysts are highly influential in various research and application fields. The catalytic performance parameters, such as catalytic activity and kinetics, were mainly characterized using the commercial-available TPD instruments (i.e., temperature-programmed desorption), which ex-situ measure the probe molecules in the gas flow. In this paper, a special-designed resonant microcantilever has been utilized as the mass-weighing component of a scientific instrument for characterizing advanced catalysts. Compared to the available TPD instruments, the proposed cantilever-based TPD instrument in-situ records the number of desorbed probe molecules (i.e., the mass-loss ∆m of the material) via the frequency-change ∆f during the heating process, and the bulky furnace and detector are not required. The cantilever-TPD instrument only consumes ng-level samples for one-time measurement, which is 6 orders of magnitude lower than the commercial TPD instrument. With a single-time in-situ TPD measurement, desorption activation energy can be directly calculated. Various catalysts (e.g., ZSM-5) have been successfully characterized by using the cantilever-TPD instrument, which is expected to become the next generation of TPD scientific instrument.