α-Fe2O3 has the rhombohedral, corundum structure and is the most common form of iron oxide. It occurs naturally as the mineral hematite, which is mined as the main iron ore. It is antiferromagnetic below 260 K and exhibits weak ferromagnetism between 260-950 K. It is easy to prepare using both thermal decomposition and precipitation in liquid phases.

1. Alpha phase
α-Fe2O3 has the rhombohedral, corundum (α-
Al2O3) structure and is the most common form. It
occurs naturally as the mineral hematite which is
mined as the main ore of iron. It is
antiferromagneticbelow ~260 K(Morin transition
temperature), and exhibits weak ferromagnetism
between 260 K and the Néel temperature, 950
K. It is easy to prepare using both thermal
decomposition and precipitation in the liquid phase
http://pubs.rsc.org/en/content/articlelanding/2014/cs/c
3cs60296f/unauth#!divAbstract
Morphology-dependent nanocatalysts: Rod-shaped oxides
Yong Lia
and Wenjie Shen*a
Author affiliations
Abstract
Nanocatalysts are characterised by the unique nanoscale properties that originate from their highly
reduced dimensions. Extensive studies over the past few decades have demonstrated that the size and
shape of a catalyst particle on the nanometre scale profoundly affect its reaction performance. In
particular, controlling the catalyst particle morphology allows a selective exposure of a larger fraction
of the reactive facets on which the active sites can be enriched and tuned. This desirable surface
coordination of catalytically active atoms or domains substantially improves catalytic activity,
selectivity, and stability. This phenomenon is called morphology-dependent nanocatalysts: catalyst
particles with anisotropic morphologies on the nanometre scale greatly affect the reaction performance

2. by selectively exposing the desired facets. In this review, we highlight important progress in
morphology-dependent nanocatalysts based onthe use of rod-shaped metal oxides with characteristic
redoxand acid–base features. The correlation between the catalytic properties and the exposed facets
verifies the chemical nature of the morphology effect. Moreover, we provide an overview of the
interactions between the rod-shaped oxides and the metal nanoparticles in metal-oxide catalyst
systems, involving crystal-facet-selective deposition of metal particles onto different crystal facets in
the oxide supports. A fundamental understanding of active sites in morphologically tuneable oxides
enclosed by the desired reactive facets is expected to direct the development of highly efficient
nanocatalysts.