論文の公開元へControlled Nanophase Separation of Alloy Towards Nanomaterials Catalyst Tailoring
概要
1.1 Background of Study
Catalysis is a phenomenon in which the rate of chemical reaction is increased with the
presence of a substance that remained unchanged after the reaction known as catalyst. It has been
one of the core components in chemistry, contributing in almost all fields, including agriculture,
energy, production and others.
Catalyst of the same phase as the reactant (gas/liquid) is termed as homogeneous catalyst,
while heterogeneous catalyst is referred to the one having different phase (solid) from the
reactant. Heterogeneous catalyst is preferred in terms of easy separation process from reactant
and low recycling cost, despite having limited surface area that lowered the interaction with
reactant molecules compared to homogeneous catalyst.
With the emergence of nanoscience, nanomaterials such as nanoparticles and nanostructured
materials have been utilized as catalysts, paving an exciting subfield of nanocatalysis.
Heterogeneous catalyst from nanomaterials provides high surface area for interaction with
reactant molecules, thus increases the catalytic activities. Nanoparticles come in variants of
metallic nanoparticles and supported catalysts while nanostructured catalyst includes nanoporous
metal, core-shell structured, hollow structured and others. With the uprising number of research
on nanomaterials catalyst, numerous synthesis routes were proposed.
Recent research trend shifted from focusing solely on increasing the surface area, to
incorporating facet tailoring in the synthesis process. This is motivated by the fact that chemical
reactions are greatly dependent to the catalyst facets. Bottom-up approach such as precipitation,
sol-gel, and reduction are conventional methods to produce nanoparticles. However, these
processes often involve laborious procedures. There are also number of successful attempts to
tailor the nanoporous materials through bottom-up approach using templates such as block
copolymers, liquid crystals and/or mesoporous silica, but these templates are far too costly for
industrialization.1–7 Top-down approach is the more practical option for mass production of
catalyst. ...
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