The acidic properties of catalysts can be measured using various techniques: 1. Temperature-Programmed Desorption (TPD): TPD involves adsorbing a probe molecule (such as ammonia) onto the catalyst surface and measuring the temperature at which it desorbs. This provides information about the strength and distribution of acidic sites. 2. Infrared Spectroscopy (IR): IR spectroscopy can identify the presence of specific acidic sites by observing changes in vibrational frequencies when probe molecules interact with the catalyst. 3. Nuclear Magnetic Resonance (NMR): NMR spectroscopy can provide detailed information about the local environment of acidic sites, helping to differentiate between Bronsted and Lewis acids.
