In the JST Strategic Basic Research Programs, Furuya Metal and Professor Hiroshi Kitagawa, Graduate School of Science, Kyoto University, have created mass production technology that empowers the constant synthesis of several nm solid-solution alloy particles, which had formerly been hard to accomplish. With this technology, we progressed in accomplishing a stable and constant synthesis of 1nm-class solid-solution alloy nanoparticles and their supported catalysts, which were difficult to obtain using general methods of liquid phase reduction reaction.
In the traditional methods, when we attempt mass-producing solid-solution alloy nanoparticles, the mixing method of elements is not consistent and the particle size distribution is broadend, making it hard to combine continuously with good quality and stability. In order to comprehend mass production technology, we have newly developed a continuous-flow production system that applies the solvothermal synthesis method and introduced it to Furuya Metal Co., Ltd. This equipment enables continuous production while keeping the quality of solid-solution alloy nanoparticles, and we are intending for mass production based on this equipment configuration.
The newly developed solid-solution alloy nanoparticles by this synthesis device are a new alloy made of metals that had been impossible to mix together. Furthermore, it is well known in many research fields including catalytic science that the physical and chemical properties of alloys dramatically change by reducing to the nanoscale. The solid-solution alloy nanoparticles are considered as innovative catalysts that purify various exhaust gases and efficiently convert raw materials into basic chemicals and energy. Therefore, they will contribute greatly to the realization of a sustainable society in environmental purification and manufacturing technologies that emit less carbon dioxide.
As a matter of fact it is already under evaluation process as an exhaust gas purification catalyst for automobiles and chemical process catalysts and we are endorsing its implementation in the society in association with private and foreign companies and research institutions.
We have progressed in establishing an economical catalyst that is far better than rhodium (Rh), which is presently used as the best catalyst, and that shows activity at low temperatures. Automotive exhaust gas distillation catalysts are good at exhaust gas distillation performance in the temperature range around 600°C, and there has been a great appeal for betterment in exhaust gas distillation conduction when the engine is not promptly warmed (cold start) after it is start. The exhaust issuance regulations for automobiles have been becoming stricter year by year, and even at such cold start, it is significant to make better the low-temperature activity that satisfies the regulation standards. The NOx conversion at 160°C of the solid-solution alloy nanoparticles was more than seven times higher than that of Rh, indicating it is an innovative one.
By applying this technology further, it is hoped to establish new solid-solution alloy nanoparticles materials that were not easy to manufacture, and practical use of solid-solution alloy nanoparticles materials that had been without mass production technology.