Japan’s position is declining in the field of artificial photosynthesis research and development. According to a survey conducted by Mitsui & Co.’s Strategic Research Institute using data from patent sites operated by German data services, the number of valid Japanese patents in this field (including pending patents) was less than half that of China, as of January 2022. China’s patents have also improved in quality in recent years. Japan is said to have led the world in this field to date, but its position is unstable.
Valid Chinese patents numbered 562 as of January 2022, a 10-fold increase from a decade ago. China surpassed Japan in valid patent numbers in 2016 and the U.S. in 2018. Many Chinese patent applications are for the domestic market, and many are said to have low value. Recently, however, an increasing number of Chinese patents have been notable international patents, such as one for a method to produce raw materials for chemicals and pesticides from carbon dioxide and hydrogen. Ishiguro Ryusuke of Mitsui & Co.’s Strategic Research Institute said, “China will probably submit a larger number of high-quality international patents applications [going forward].”
China is making great strides in basic research, an area where China used to mostly follow the lead of other countries. In September 2021, a Chinese research institute published the results of artificial starch synthesis in the U.S. journal Science. This process is said to be the most difficult to imitate among plant photosynthesis processes. The team analyzed and reproduced the complex reactions in detail, enabling it to become one of the world’s most advanced research teams.
The number of valid Japanese patents increased 3.8 times in 10 years to reach 269, but this is a smaller increase compared to that of China. Japan’s number of patents is on par with that of the U.S., which has 213. Although there are companies such as Fujifilm and Toyota Central R & D Labs that boast one of the highest numbers of patent applications in the world, Japanese companies in general have not been able to keep up with the sheer number of China’s patents.
Artificial photosynthesis, a process which creates resources, is a dream technology for Japan, a resource-poor country. There are many researchers whose achievements are considered to be “Nobel Prize candidates,” such as Fujishima Akira of the Tokyo University of Science who discovered the “Honda-Fujishima effect” in which a photocatalyst breaks down water into oxygen and hydrogen, and Jian-Ren Shen of Okayama University who explained the crystal structure of proteins essential for photosynthesis in plants. Some think that while research activities in this area declined in Europe and the U.S. after the 1970s oil crisis, Japan continued its research, giving it a technological advantage.
The established view was that Japan maintained a high level of competitiveness by amassing research experience. An objective look at Japan’s patent numbers, however, shows this view is outdated. Germany and some other European countries are said to have more patent applications with high value amid the decarbonization trend. Japan’s status may decline even further in the future.