Trends and future challenges in hydrogen production and storage research.

With the rapid industrialization, increasing of fossil fuel consumption and the environmental impact, it is an inevitable trend to develop clean energy and renewable energy. Hydrogen, for its renewable and pollution-free characteristics, has become an important potential energy carrier. Hydrogen is regarded as a promising alternative fuel for fossil fuels in the future. Therefore, it is very necessary to summarize the technological progress in the development of hydrogen energy and research the status and future challenges. Hydrogen production and storage technology are the key problems for hydrogen application. This study applied bibliometric analysis to review the research features and trends of hydrogen production and storage study. Results showed that in the 2004-2018 period, China, USA and Japan leading in these research fields, the research and development in the world have grown rapidly. However, the development of hydrogen energy still faces the challenge of high production cost and high storage requirements. Photocatalytic decomposition of water to hydrogen has attracted more and more research in hydrogen production research, and the development of new hydrogen storage materials has become a key theme in hydrogen storage research. This study provides a comprehensive review of hydrogen production and storage and identifies research progress on future research trend in these fields. It would be helpful for policy-making and technology development and provide suggestions on the development of a hydrogen economy.