Atomically Precise Gold Catalysis - Atomically-Precise Methods for Synthesis of Solid Catalysts - page 114

pathways of selective reduction of acetic acid to acetaldehyde. DFT calcula-
tions on modes and energies of adsorption of the involved intermediates
along with the overall reaction energies were used for this study. In a dif-
ferent report, Malheiro et al. 104 have investigated the effect of oxygen re-
duction reaction (ORR) in fuel cells containing Pt-M/C catalysts (M ¼ 3d
transition metals) by characterizing the electronic properties of Pt-Fe/C
catalysts using in situ dispersive X-ray absorption spectroscopy (DXAS) to
assess their dependence on Fe content and to analyze its correlation with
ORR activity.
Recently, Liu et al. 39 explored the catalytic oxidation of styrene using two
different gold cluster catalysts which have same atomic core size of
25 atoms, but different geometric and electronic structure. Using a com-
bination of synchrotron radiation-based X-ray absorption fine structure
spectroscopy (XAFS) and ultraviolet photoemission spectroscopy (UPS), the
authors have found a direct correlation between the catalytic selectivity of
the styrene oxidation reaction with the electronic structure of the
nanoclusters. They have concluded that more electropositive nature of the
cluster would yield more oxidized products in the reaction and vice versa.
Due to the advances being made in the synthesis of atomically precise
catalysts, it has now become possible to investigate more thoroughly the
correlation between their electronic structure and catalytic properties.
These studies in near future are anticipated to pave way for a better
understanding of the atomically-precise information related to molecular
activation and reaction mechanisms leading to superior design of catalysts
with required performance.

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4.5 Correlation of Magnetic Structure-Catalysis
Relationship
The correlation between magnetism and catalysis has been extensively in-
vestigated since past century and was reviewed as early as 1946 by P. W.
Selwood 105 from Northwestern University, USA. There are several examples
that have been elucidated in that review to highlight the effect of magnetism
on catalytic activity of different magnetic metals and metal oxides. For in-
stance, a linear relation between magnetization and catalytic activity was
observed for hydrogenation of benzene on Ni-Cu catalyst at 175 1C. 106 The
results showed that an active catalyst is quite strongly ferromagnetic, and
that heating the catalyst produced a loss of ferromagnetism. This loss of
ferromagnetism occurred in a linear relationship to the loss of catalytic ac-
tivity (Figure 4.17).
In a different example, the catalytic activity of pure Ni metal for nitrous
oxide decomposition near its Curie point was found to increase exponen-
tially 107 due to sharp increase in the temperature coecient of reaction
velocity at the Curie temperature. The catalytic activity was also shown to be
affected by magnetism through the change in binding energies of the