Hiroshige Matsumoto

Bio: Hiroshige Matsumoto is an academic researcher from Nagasaki University. The author has contributed to research in topics: Hydrogen & Catalysis. The author has an hindex of 18, co-authored 48 publications receiving 1068 citations. Previous affiliations of Hiroshige Matsumoto include Toyota & University of Connecticut.

Sonochemical Preparation and Catalytic Behavior of Highly Dispersed Palladium Nanoparticles on Alumina.

Abstract: Palladium nanoparticles dispersed on Al2O3 were prepared via the sonochemical reduction of tetrachloropalladate(II) (Pd(II)) in an aqueous solution. The reduction of Pd(II) to metallic Pd successfully proceeded, even in the presence of Al2O3 powder, by ultrasonic irradiation at 200 kHz. The rates of Pd(II) reduction strongly depended on the type of alcohol additive, which acts as an effective accelerator for Pd(II) reduction. The dispersion of metallic Pd particles on the Al2O3 surface was appreciably enhanced by increasing the rate of reduction. By UV−visible, pH, and transmission electron microscopy measurements, the major pathway in the formation of Pd nanoparticles on Al2O3 was speculated to proceed via the following three steps: (1) the reduction of Pd(II) ions proceeds with reducing radicals formed by sonolysis of water and alcohol molecules, resulting in the formation of Pd nuclei, (2) the growth and/or the agglomeration of the Pd nuclei rapidly occurs to form Pd nanoparticles, and (3) the Pd part...

The renaissance of iron-based Fischer-Tropsch synthesis: on the multifaceted catalyst deactivation behaviour.

Abstract: Iron-based Fischer–Tropsch catalysts, which are applied in the conversion of CO and H2 into longer hydrocarbon chains, are historically amongst the most intensively studied systems in heterogeneous catalysis. Despite this, fundamental understanding of the complex and dynamic chemistry of the iron–carbon–oxygen system and its implications for the rapid deactivation of the iron-based catalysts is still a developing field. Fischer–Tropsch catalysis is characterized by its multidisciplinary nature and therefore deals with a wide variety of fundamental chemical and physical problems. This critical review will summarize the current state of knowledge of the underlying mechanisms for the activation and eventual deactivation of iron-based Fischer–Tropsch catalysts and suggest systematic approaches for relating chemical identity to performance in next generation iron-based catalyst systems (210 references).

Plasma technology - a novel solution for CO2 conversion?

Abstract: CO2 conversion into value-added chemicals and fuels is considered as one of the great challenges of the 21st century. Due to the limitations of the traditional thermal approaches, several novel technologies are being developed. One promising approach in this field, which has received little attention to date, is plasma technology. Its advantages include mild operating conditions, easy upscaling, and gas activation by energetic electrons instead of heat. This allows thermodynamically difficult reactions, such as CO2 splitting and the dry reformation of methane, to occur with reasonable energy cost. In this review, after exploring the traditional thermal approaches, we have provided a brief overview of the fierce competition between various novel approaches in a quest to find the most effective and efficient CO2 conversion technology. This is needed to critically assess whether plasma technology can be successful in an already crowded arena. The following questions need to be answered in this regard: are there key advantages to using plasma technology over other novel approaches, and if so, what is the flip side to the use of this technology? Can plasma technology be successful on its own, or can synergies be achieved by combining it with other technologies? To answer these specific questions and to evaluate the potentials and limitations of plasma technology in general, this review presents the current state-of-the-art and a critical assessment of plasma-based CO2 conversion, as well as the future challenges for its practical implementation.

Carbon-Supported Pt and PtRu Nanoparticles as Catalysts for a Direct Methanol Fuel Cell

Abstract: Nanosized Pt and PtRu colloids were prepared by a microwave-assisted polyol process and transferred to a toluene solution of decanthiol Vulcan XC-72 was then added to the toluene solution to adsorb the thiolated Pt and PtRu colloids TEM examinations showed nearly spherical particles and narrow size distributions for both supported and unsupported metals The carbon-supported Pt and PtRu nanoparticles were activated by thermal treatment to remove the thiol stabilizing shell All Pt and PtRu catalysts (except Pt23Ru77) showed the X-ray diffraction pattern of a face-centered cubic (fcc) crystal structure, whereas the Pt23Ru77 alloy was more typical of the hexagonal close-packed (hcp) structure The electro-oxidation of liquid methanol on these catalysts was investigated at room temperature by cyclic voltammetry and chronoamperometry The results showed that the alloy catalyst was catalytically more active than pure platinum The heat-treated catalyst was also expectedly more active than the non-heat-treate