Evaluation and analysis of fuel cells is an indispensable technology for improving the performance and durability of fuel cells in the future. On the other hand, not all evaluation protocols for each evaluation item set as the development target have been prepared. From the perspective of maintaining and improving international competitiveness, it is important to develop functional targets, corresponding evaluation items, and evaluation protocols that are expected to be deployed in HDV, etc. In the latter part, we overview the domestic development status of advanced PEFC analysis technologies that enhance international competitiveness in PEFC development.

Platinum skin-covered Pt-M alloy (M=Fe, Co, Ni) nanocatalysts supported on carbon exhibited superlative mass activity for the hydrogen oxidation reaction (HOR) with high CO-tolerance and robustness with respect to air exposure, as novel anode catalysts for the polymer electrolyte fuel cell (PEFC). H₂O₂ is produced when O₂ gas diffuses through the polymer electrolyte membrane (PEM) to the conventional Pt/C hydrogen anode in PEFC. H₂O₂ is the precursor of ・OH radicals, which degrade PEM seriously. It was found for the first time that H₂O₂ production rate at Pt skin-PtCo/C anode during the HOR was suppressed greatly at a practical temperature of 80°C. A remarkably longer lifetime of a PEM with new PtCo/C anode than the case of commercial Pt/C anode has been demonstrated in an accelerated stress test of a single cell. These excellent properties of Pt skin-PtCo have been analyzed multilaterally.

To solve a common problem with the industry towards full-scale dissemination of fuel cell vehicles, it is necessary to achieve the target performance of fuel cells after 2030. In order to achieve the performance, University of Yamanashi, seven corporations, and three other universities are jointly working on the “Electrolytes, Catalysts and Catalyst layers with Extraordinary Efficiency, power and Durability for PEFCs” project (hereinafter referred to as ECCEED’30) as a NEDO project. In this project, the following three themes are being implemented. 1. “Research and development of catalysts that achieve high efficiency, high output, and high durability” 2. “Research and development of hydrocarbon-based electrolyte materials that achieve high efficiency, high output, and high durability” 3. “Research and development of catalyst layer that realizes high efficiency, high output and high durability” This article describes the recent technical achievements from each theme.

Reduction of the usage of platinum, which is used as a catalyst, in polymer electrolyte fuel cells (PEFCs) is one of the most important issues for the widespread commercialization of fuel cell vehicles. To achieve the activity in the 2030 NEDO target, development of highly active and durable Pt core-shell and alloy catalysts was started in 2020 by five academic and industrial institutions focusing on the following innovative technologies: 1) innovative core-shell catalyst technology, 2) innovative surface modification with special organic compounds, 3) innovative supporting materials with high surface areas interconnected pores, 4) innovative proton conduction within the pores of supporting materials using ionic liquids. In this review article, the background and recent activities on the development of Pt core-shell catalysts in our project are overviewed.

The development of Pt-free cathode catalysts is strongly desired for globalization of proton exchange membrane fuel cells. While several research groups have demonstrated quite promising fuel cell performances using Fe-based cathode catalysts, the catalytic activity and durability of Pt-free catalysts need to be further improved. This article overviews the recent progress on the development and mechanistic study of the Pt-free cathode catalysts prepared by pyrolyzing Fe, N and C containing precursors. Furthermore, the development of Fe complexes aiming for the catalyst synthesis without pyrolysis is also discussed.

Reducing the overpotential for the oxygen reduction reaction (ORR) is necessary to increase the energy transformation efficiency of polymer electrolyte fuel cells (PEFCs). We have focused on oxides of group 4 (or 5) elements as alternatives to the current Pt catalysts: Those oxides are stable under the PEFC environment and can exhibit activity for the ORR, and recently, ideal active sites were found in such oxides by simulation. This clearly points out the strong potentiality of oxide-based materials to reach the equilibrium potential for the ORR. In more details, first-principle calculation indicated that two potential active sites which surpass Pt catalysts can be formed at oxide surfaces by (i) substitutional dopants (e.g., Pd and Rh) at the titania surface, and (ii) formation of stable oxygen vacancies at the surface of zirconium oxides. Being different from the simulation, the actual catalysts need electron transfer to the catalyst active sites and those oxides above mentioned are semiconductors with large band-gaps, hence carbon additives are often needed for the catalysts to form an appropriate electron conduction path from electric conductive supports to the active sites on the oxide surface. Careful analyses of such catalysts with carbon additives, we found that the crystalline structures of the titanium oxides (or atomic arrangements) and oxygen vacancies of the zirconium oxides were of great importance for the ORR activity. We also report the investigation of adsorbed oxygen species by the temperature programmed desorption.

While polymer electrolyte fuel cells using hydrogen or reformed hydrogen have now been implemented into practical applications, large scale employment is necessary to make an impact towards the carbon neutral society. The decrease in Pt usage is crucial to meet the strong demand for cost competitive and environmentally benign power sources, and thus game-changing technologies must be developed to realize highly active and durable electrocatalysts. In this article, state-of-the-art technologies relating to Pt-based electrocatalysts with two-dimensional nanosheet structures will be outlined. The synthesis of Pt-based nanosheet catalysts with core-shell structure that exhibits oxygen reduction reaction activity and stability higher than standard carbon supported Pt will be described. Synthesis of poly- and single-crystalline Pt nanosheets via graphene oxide templating will be presented. An advanced catalyst layer fabrication technique via galvanostatic replacement directly in the catalyst layer will be given. In addition, commercial scale processes of electrocatalysts with nanosheet and core-shell structures are reported.

In the world, CO₂ emission reduction is a very important issue. Introducing large-mass-hydrogen-energy is being expected to expand hydrogen application, or to solve the energy issues. In December 2017, the Japanese government announced a Basic Hydrogen Strategy for introducing hydrogen energy supply chain. Under these circumstances, imported CO₂-free hydrogen will be one of the solutions for energy security and CO₂ reduction. To achieve this, a pilot demonstration has been already commenced in 2020 aiming at commercialization of CO₂-free hydrogen supply chain in the period of 2030’s. The pilot demonstration is comprised of hydrogen production from Australian brown coal, local transportation, loading liquefied hydrogen onto the bulk carrier, world’s first offshore transportation of large volume of liquefied hydrogen between Japan and Australia, and unloading at the Kobe terminal. Kawasaki Heavy Industries, Ltd. has been promoting the “Hydrogen Energy Supply Chain (HESC)” Project. In this report, the followings are shown: a concept of the supply chain and the progress of construction and demonstration of each part of the supply chain, especially for liquefied hydrogen carrier.

Chiyoda have been continuing the technology development employing liquid organic hydrogen carrier (LOHC) as large-scale storage and transportation technology for hydrogen since 2002. Chiyoda succeeded the development of the dehydrogenation catalyst through the fundamental research for around ten years. After completing the establishment of the system technology through a pilot plant demonstration in 2014, Chiyoda has been preparing to participate in a project by NEDO to demonstrate an international hydrogen supply chain in large-scale, and in 2020, the project was successfully completed between Brunei Darussalam in Southeast Asia and the Kawasaki waterfront area in Japan for 5,000 km. “SPERA Hydrogen®” System has been shift to commercialization phase due to completion of the International Hydrogen Supply Chain Demonstration including whole process. This paper introduces outline and the features of the SPERA hydrogen system, and the international hydrogen supply chain demonstration funded by NEDO.

Japan and Germany, two world leaders of hydrogen development, recently adopted national hydrogen strategies. Japan highlights hydrogen as an energy carrier for clean and stable import of energy, while Germany for the conversion of excessive renewable electricity to heat use in industry sector. Germany also takes active approach to launch hydrogen market by stimulating both demand and supply of hydrogen. It is an advantage of Germany who can make use of carbon pricing to boost the cost competitiveness of hydrogen. Japan should consider taking proactive approach to generate the demand of hydrogen if it wants to maintain its advantage in hydrogen development. Currently cost competitiveness of hydrogen is far behind fossil fuels. In order to overcome this, the environmental value of hydrogen should be evaluated properly and taken into account in the choice of energy mix.

Survey on the interest from private companies was conducted to establish effective cooperation between academia and industry toward CO₂ free society by challenging innovations in the 3 fields of renewable energy, hydrogen and maritime technologies. This approach of integrating the 3 field technologies was supported in general but various potential deviations in methodologies were exposed. However, these findings will be a useful hint to promote further cooperation among wider sectors and contribute to the social implementation of innovations to realize CO₂ free society.