<p>Ion
soft landing is a preparative mass spectrometry technique that enables intact
deposition of polyatomic ions onto surfaces. The ability to select ions with
well-defined mass, charge, and kinetic energy, along with precise control over
size, shape, and position of the ion beam in the deposition process
distinguishes ion soft landing from traditional synthetic and surface
preparation approaches. A wide range of projectile ions including molecular
ions, non-covalent complexes, clusters, and
ionic fragments generated in the gas phase have been used in
soft-landing studies to address both the fundamental questions related to
ion-surface interactions and enable applications of hyperthermal beams.</p>
<p>Since
the first soft landing instrument was implemented by Cooks and co-workers in
1977, significant advances have been achieved in preparative mass spectrometry
instrumentation. Current instrument development efforts are focused on
obtaining high ion currents, increasing the experimental throughput, and
developing capabilities for layer-by-layer deposition. In chapter 2 and 3, two
novel instrumentation approaches are introduced, which improve the ion flux and
experimental throughput of ion soft landing research. In particular, soft
landing of ions of both polarities enables the bottom-up construction of ionic
materials. Meanwhile, a rotating wall mass analyzer substantially increases the
mass range of mass-selective deposition and disperses multiple species on the
same surface thereby increasing the experimental throughput. These
instrumentation developments open up the opportunities to explore research
topics in the field of catalysis, energy storage and production, biology, and
quantum sciences.</p>
<p>In
chapter 4, I describe a novel <i>in situ</i> spectroelectrochemistry approach
for studying structural changes of electroactive species during electrochemical
processes. In these experiments, ion soft landing is used to prepare
well-defined ions at electrochemical interfaces. In addition, understanding of the
gas-phase properties of cluster ions is important for their application in ion
soft landing research. Ions can be prepared in the proper physical and chemical
state via gas-phase chemistry approaches, and the favorable properties and
reactivities of ions can thereby be harnessed using ion soft landing. In
chapter 5 and 6, gas phase properties of host-guest complexes of cyclodextrins
and polyoxometalates and molybdenum halide clusters are discussed.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/13369562 |
| Date | 12 December 2020 |
| Creators | Pei Su (9762467) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/Preparative_Mass_Spectrometry_Instrumentation_and_Applications/13369562 |
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