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The unique anisotropic physical properties of columnar discotic liquid crystals (DLCs) have attracted considerable interest for their potential applications as electronic devices, such as field effect transistors (FETs), [1,2] photovoltaics, [3] and light emitting diodes (LEDs). [4,5] The typical DLC molecule consists of a relatively rigid aromatic core with several flexible aliphatic side chains. Depending on their molecular structure and thermodynamic state, DLCs exist in various phases such as nematic, hexagonal columnar and rectangular columnar. [6] In the columnar phase, the intermolecular p-p orbital overlap between neighboring aromatic cores is significant, providing extremely anisotropic and order-dependent, quasi-one-dimensional, charge carrier mobility along the stacked cores. [7,8] For many practical applications, however, it is crucial to obtain a thin film of uniaxially oriented and highly ordered columnar superstructures of DLC molecules covering the macroscopic area of a substrate. [9] For example, the unidirectional 'edge-on' alignment, with the DLC columnar directors parallel to the substrate, is required for field effect transistors. On the other hand, the 'face-on' arrangement, with DLC columnar directors perpendicular to the substrate, is generally best for photovoltaic devices and light emitting diodes. [10] Recently, various alignment techniques utilizing temperature gradient, [11] concentration gradient, [12] pre-aligned layer, [13] electric field [14] and magnetic field [15] have been reported. However, more facile approaches to achieve uniaxially oriented long-range ordering of DLC columnar superstructures with clear identification of the ordered structures are still being actively explored.Here, we report a simple method to obtain a uniaxially oriented and highly ordered columnar superstructure of a DLC, using the alkyl-substituted metalloporphyrinoid, cobalt octa(n-decylthio)porphyrazine (CoS10), on substrates over a centimeter length scale. This method simultaneously utilizes the interactions of DLCs with both an easily accessible external magnetic field (ca. 1.0 T) and a functionalized surface of substrate. The substrate was functionalized with octadecyltrichlorosilane (OTS) to increase the affinity of the surface with the alkyl side chains of the discotics, resulting in an 'edge-on' arrangement of DLC columns. The detailed structures of the ordered and oriented columnar DLCs on substrates were investigated using the grazing incidence small angle X-ray scattering (GISAXS) technique, which is a very powerful tool to investigate the internal nanoscale structures in thin films. [16,17] The GISAXS measurements show that when a spin-coated CoS10 thin film on an OTS-functionalized silicon wafer is cooled from its isotropic phase to the liquid crystal phase in the presence of an external magnetic field of 1.07 T, it forms highly oriented 'edge-on' columnar superstructures with the columnar directors perpendicular to the applied magnetic field. The oriented superstructure shows a long range o...

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Direct synthesis of dimethyl ether (DME) from synthesis gas was investigated on bifunctional catalysts, containing Cu-ZnO-Al 2 O 3 promoted with Zr or Ga on γ-Al 2 O 3 as a methanol dehydration catalyst. In comparison to an unpromoted bifunctional catalyst, promoted catalysts with Zr or Ga showed a higher catalytic performance and stability. The facile reducibility of copper particles with high dispersion and an appropriate acidity and electronic state of copper species are mainly responsible for the superior catalytic performance with the help of structural promoting effects of Ga or Zr components on Cu-ZnO-Al 2 O 3 . The high formation rate of methanol by CO hydrogenation on the Zr-promoted Cu-ZnO-Al 2 O 3 and the dehydration rate of methanol to DME on the modified acidic sites of γ-Al 2 O 3 are mainly responsible for the superior catalytic activity and stability.

Recently, air pollution has worsened throughout the world, and as regulations on nitrogen oxides (NOx) are gradually tightened many researchers and industrialists are seeking technologies to cope with them. In order to meet the stringent regulations, research is being actively conducted worldwide to reduce NOx-causing pollution. However, different countries tend to have different research trends because of their regional and industrial environments. In this paper, the results of recent catalyst studies on NOx removal by selective catalytic reduction are reviewed with the sources and regulations applied according to the national characteristics of South Korea. Specifically, we emphasized the three major NOx emissions sources in South Korea such as plant, automobile, and ship industries and the catalyst technologies used.