nl4015292_si_001.pdf (2.88 MB)
Restructuring Transition Metal Oxide Nanorods for 100% Selectivity in Reduction of Nitric Oxide with Carbon Monoxide
journal contribution
posted on 2016-02-19, 03:58 authored by Shiran Zhang, Junjun Shan, Yuan Zhu, Luan Nguyen, Weixin Huang, Hideto Yoshida, Seiji Takeda, Franklin (Feng) TaoTransition metal oxide is one of
the main categories of heterogeneous
catalysts. They exhibit multiple phases and oxidation states. Typically,
they are prepared and/or synthesized in solution or by vapor deposition.
Here we report that a controlled reaction, in a gaseous environment,
after synthesis can restructure the as-synthesized transition metal
oxide nanorods into a new catalytic phase. Co3O4 nanorods with a preferentially exposed (110) surface can be restructured
into nonstoichiometric CoO1–x nanorods.
Structure and surface chemistry during the process were tracked with
ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and environmental
transmission electron microscopy (E-TEM). The restructured nanorods
are highly active in reducing NO with CO, with 100% selectivity for
the formation of N2 in temperatures of 250–520 °C.
AP-XPS and E-TEM studies revealed the nonstoichiometric CoO1–x nanorods with a rock-salt structure as the active
phase responsible for the 100% selectivity. This study suggests a
route to generate new oxide catalysts.