Substrate/surface characterization spectrometry

Block and co-workers [35] modified the atom probe to develop a method called pulsed-field desorption mass spectrometry (PFDMS), whereby a short high-voltage pulse desorbs all species present on the tip during a catalytic reaction. The repetition frequency of the field pulse controls the time for which the reaction is allowed to proceed. Hence, by varying the repetition frequency between desorption pulses in a systematic way, one can study the kinetics of a surface reaction [35], In fact, this type of experiment - where one focuses on a facet of desired structure, which may include steps and defects - comes close to one of the fundamental goals of catalyst characterization, namely studying a catalytic reaction on substrates of atomically resolved structure with high time resolution. 

One of the most important recent developments in characterizing SAMs, is the use of MALDI-TOF mass spectrometry to directly image molecules chemisorbed to gold surfaces [230]. In a series of articles, Mrksich and coworkers demonstrated convincingly that the technique is also extremely useful in analyzing reactions on monolayers [231]. No special equipment is necessary and a gold-coated substrate can simply be placed in a standard MALDI mass spectrometer. Any... 

---