Adsorption microcalorimetry: recent advances in instrumentation and application.

Adsorption microcalorimetry measures the energetics of adsorbate-surface interactions and can be performed by use of several different techniques. This review focuses on three methods: single-crystal adsorption calorimetry (SCAC), isothermal titration calorimetry (ITC), and electrochemical adsorption calorimetry. SCAC is a uniquely powerful technique that has been applied to a variety of atoms and molecules that represent a large variety of well-defined adsorbate species on a wide range of single-crystal surfaces. ITC and electrochemical microcalorimetry are useful for studying adsorption energies in liquid solutions (on surfaces of suspended powders) and at the electrode-electrolyte interface, respectively. Knowledge of the energetics of adsorbate formation is valuable to ongoing research in many fields, including catalysis, fuel cells, and solar power. In addition, calorimetric measurements serve as benchmarks for the improvement of computational approaches to understanding surface chemistry. We review instrumentation and applications, emphasizing our own work.