Editing Surface science (section)

===Catalysis===
The adhesion of gas or liquid molecules to the surface is known as [[adsorption]]. This can be due to either [[chemisorption]] or [[physisorption]], and the strength of molecular adsorption to a catalyst surface is critically important to the catalyst's performance (see [[Sabatier principle]]). However, it is difficult to study these phenomena in real catalyst particles, which have complex structures. Instead, well-defined [[single crystal]] surfaces of catalytically active materials such as [[platinum]] are often used as model catalysts. Multi-component materials systems are used to study interactions between catalytically active metal particles and supporting oxides; these are produced by growing ultra-thin films or particles on a single crystal surface.<ref>{{Cite journal | doi=10.1103/PhysRevB.81.241416| bibcode=2010PhRvB..81x1416F| title=Particle-size dependent heats of adsorption of CO on supported Pd nanoparticles as measured with a single-crystal microcalorimeter| year=2010| last1=Fischer-Wolfarth| first1=Jan-Henrik| last2=Farmer| first2=Jason A.| last3=Flores-Camacho| first3=J. Manuel| last4=Genest| first4=Alexander| last5=Yudanov| first5=Ilya V.| last6=Rösch| first6=Notker| last7=Campbell| first7=Charles T.| last8=Schauermann| first8=Swetlana| last9=Freund| first9=Hans-Joachim| journal=Physical Review B| volume=81| issue=24| pages=241416| hdl=11858/00-001M-0000-0011-29F8-F| hdl-access=free}}</ref>

Relationships between the composition, structure, and chemical behavior of these surfaces are studied using [[ultra-high vacuum]] techniques, including adsorption and [[Thermal desorption spectroscopy|temperature-programmed desorption]] of molecules, [[scanning tunneling microscopy]], [[low energy electron diffraction]], and [[Auger electron spectroscopy]]. Results can be fed into chemical models or used toward the [[rational design]] of new catalysts. Reaction mechanisms can also be clarified due to the atomic-scale precision of surface science measurements.<ref>{{Cite journal |doi = 10.1016/j.cattod.2011.08.033|title = Scanning tunneling microscopy evidence for the Mars-van Krevelen type mechanism of low temperature CO oxidation on an FeO(111) film on Pt(111)|year = 2012|last1 = Lewandowski|first1 = M.|last2 = Groot|first2 = I.M.N.|last3 = Shaikhutdinov|first3 = S.|last4 = Freund|first4 = H.-J.|journal = Catalysis Today|volume = 181|pages = 52–55|hdl = 11858/00-001M-0000-0010-50F9-9|hdl-access = free}}</ref>