Project Overview

In many functional materials, the local structure of the “dopant,” “hetero-interface,” and “nanomaterial,” i.e.,
the “Active-Sites,”
in the parent material play a vital role in the functional expression of the material. However, there are hardly any examples where the active-site structure has been determined accurately. Japan has targeted these active-sites and is currently at the top with regard to the research and development of a technology enabling three-dimensional (3D) imaging at an atomic resolution. This field, termed “3D active-site science,” is a novel foundational innovative area that involves a new scientific field, which will give breakthrough for materials science, green science and life science by
blending various scientific theories and introducing a next-generation measurement technology that meets the needs of the advanced sample-synthesis technology and cutting-edge computer science.
 This project aims at introducing a path for the creation of new devices and scientific theories through profound measurement-based investigations into how the active-sites coordinate with the peripheral atoms to cause 3D functional expressions in a very wide range of samples, such as catalysts, solar cells, spintronic materials, and protein molecules.

Necessity of fusion research

 Three categories of 3D atomic imaging technologies have been developed thus far in Japan:

(1)    With doped-atom holography, which employs photoelectrons and fluorescent X-rays, it is possible to visualize the atomic arrangement around the adsorbates and impurities in an area of several nanometers.

(2)    Surface and interface holography reproduces the atomic arrangement involved in the functional expression of the surface and interface based on the surface X-ray diffraction.

(3)    Nanostructure imaging enables the measurement of nanoparticles or even a single protein molecule by applying the phase-retrieval technique to the electron diffraction pattern in order to reproduce the atomic image.

 Using these techniques, in the case of catalytic reactions, for example, it is possible to elucidate the entire picture of the active areas. This is achieved by analyzing the periphery of the reaction-center atoms by using (1), the junction interface of the nanoparticle catalyst and the substrate by using (2), and the nanoparticles themselves by using (3).

 Thus, by using multiple measurement methods, it is possible to measure and analyze the active-sites in a versatile manner. Furthermore, it is possible to transcend the conventional research areas and systematize and integrate them as a single scientific theory.

What do we elucidate?
1)    By applying multiple 3D atomic-imaging techniques to a single sample and using the latest algorithms, we obtain 3D information about the active-sites from the comprehensive data. Furthermore, while we study the stability using the first-principle calculations, we also clarify the unique electronic and optical properties, conductivity, and reactivity expressed by the 3D local structures, and we present the guidelines for designing a 3D local structure with more desirable properties.

2)    We also perform measurements at conditions close to the atmospheric pressure for a wide range of materials, including soft and bio-type materials that are considered difficult to measure. We also implement methods that enable high-speed time-division measurements during catalytic reactions.

3)    Then, we build an active-site atomic structure database (followed by web publication, the first of its kind in the world) to centralize the obtained data so that they are useful for the enhancement of various methods. The data also serve as the basis for an integrated material-science understanding as well.

4)    We actively perform measurements for many functional materials—including those studied in publicly funded research, such as protein molecules, organic solar cells, catalysts, and spintronic materials—understand the role of atomic active-sites, and provide findings regarding the creation of new materials.

Our course of action for the development of this academic area

 By developing this new academic area, we aim to enable active participation and exchange between researchers, so that many researchers from different fields can contribute to this field. Furthermore, we intend to perform collaborative research, including exchanges with overseas researchers and the use of overseas facilities. We aim to take the initiative to play a guiding role overseas, not only in Europe and America but also in Asia, and form an international research community. Then, we intend to greatly expand the field of 3D active-site science and link this technology to the industrial world, thereby enhancing the scope of the field. Thus, by disseminating the results of this academic area to domestic and foreign industries, we intend to firmly establish our international presence and form a global base called the Center for 3D Active-Site Science that will realize significant improvements and enhancements of Japan’s science and technology.