• Creation of inorganic ions at atmospheric pressure
  • Deposition of mass-selected ions to generate catalytic surfaces
  • Subsequent analysis of surface characteristics and reactivity


Key Findings

  • APTDI can generate simple mass spectra for inorganics
  • APTDI can also create mixed-metal clusters
  • Mixed-metal surfaces show increased reactivity


Ionization of Inorganics

Atmospheric pressure thermal desorption ionization (APTDI) is capable of generating simple cluster ions from inorganic species; mixed-metal clusters can also be generated from inorganic mixtures via APTDI:

Soft landing instrument design: Currents of 200pA have been measured at the surface (without ion funnel).


  • Dr. R. Graham Cooks (professor)
  • Zongxiu Nie (post-doctoral student)
  • Michael Goodwin (graduate student)
  • Aliah Dugas (graduate student)

Full list of personnel



We have found that many inorganic complexes will form protonated monomers, dimers and trimers upon heating:

Mixtures of complexes will form mixed dimers, trimers, etc. upon heating:


Electrosprayed Jacobsen's catalyst ions have been landed (with no mass selection). The landing surface was then rinsed;the ESI mass spectrum of the resulting solution clearly demonstrates successful landing:

Soft landing experiments have also been performed at Julia Laskin's lab at PNNL. Surfaces prepared containing both protonated VO(salen) and Ni(salen) species displayed increased redox reactivity relative to pure VO(salen) or Ni(salen) surfaces.



  • Publication to be submitted to JACS or Angew. Chem. in the near future describing APTDI results and soft landing experiments at PNNL

Full publications list