【HaiChuan. Pioneers in the Chemical Industry】06 Cai Liuseng – One of the founders of catalytic kinetics research in China, and a pioneer in photochemical research

Cai Liuseng (September 1902 – October 1983), from Quanzhou, Fujian Province. A renowned physical chemist, elected an academician of the Chinese Academy of Sciences in 1957. Graduated from Yenching University in 1924 and stayed on to teach there. In 1929, he went to the United States to study, pursuing a doctorate in photochemistry and catalytic reaction kinetics at the University of Chicago’s Department of Chemistry. He received his doctorate in 1932 and returned to the Department of Chemistry at Yenching University to teach in the same year. In 1948, he went to the United States again and was invited to serve as a visiting scholar at the University of Washington. He returned to the country on the eve of the founding of the People’s Republic of China in 1949. In 1952, in response to the call, he went to Northeast People’s University (the predecessor of Jilin University) and worked closely with Professors Tang Aoqing, Guan Shizhi, and Tao Weisun to establish the Department of Chemistry. During his lifetime, Cai Liusheng served as a director of the Chinese Chemical Society, vice president of the Changchun Science and Technology Society, an editorial board member of Chemical Bulletin, and a delegate to the third and fifth National Congresses. He held the position of head of the Department of Chemistry at Jilin University for many years, and he joined the Communist Party of China in 1982. Cai Lisheng dedicated his entire career to teaching and research in physical chemistry; he was one of the founders of catalytic kinetics research in China and a pioneer in photochemistry research. After returning to China in 1932, he collaborated with Professor Ge Tingsu from the Department of Physics at Yenching University to study the \"ultraviolet absorption spectrum of rotenone\" and the \"photochemical decomposition of rotenone\"” ； Meanwhile, he has successively published over 10 research papers on physical chemistry topics such as \"solution adsorption\" in domestic and international academic journals. In 1948, while serving as a visiting scholar at the University of Washington in the United States, Cai Liuseng collaborated with professors from Carmen University to develop the application of tracer atom technology in chemical research. Their pioneering research demonstrated that tracer atom technology is one of the most effective methods for studying the kinetics of chemical reactions. This technology is still widely used to this day. Not long after the establishment of the Department of Chemistry at Jilin University, Cai Lisheng personally participated in and supervised young teachers and laboratory technicians in their research work. He quickly developed devices such as the \"capillary high-pressure mercury lamp,\" the \"hydrogen spectrum lamp,\" and the \"Geiger counter,\" filling gaps in domestic technology at that time ； The research team he supervised quickly achieved significant scientific results, and gradually a national center for catalytic kinetics was established, open to various institutions across the country. In 1963, Cai Liuseng led the establishment of a research laboratory in catalytic kinetics, which was designated as a **key research institution and tasked with carrying out a major fundamental research project titled ‘Oxidation of methane to formaldehyde’**. In carrying out this research, under his personal participation in the experiments and guidance, the research laboratory mastered the rules for the synthesis, storage, and decomposition of the intermediate product methyl hydroperoxide, reaching an international standard in academia at that time. To understand the microscopic reaction processes and mechanisms, he organized efforts to develop modern physical experimental methods such as mass spectrometry, chromatography, and flash photolysis. The flash photolysis apparatus was capable of being used to study chemical reactions on the microsecond scale by 1964, filling a gap in domestic research. Starting in the 1930s, he focused on applying the emerging modern physical techniques to chemical research, carrying out a series of pioneering works in China. He was the first to introduce technologies such as vacuum technology (1947), tracer atoms (1948), and flash spectroscopy (1964) to China’s chemical community, making significant contributions to the development of experimental physical chemistry in the country. Since 1974, many pioneering studies have been conducted in fundamental research areas such as light- and laser-induced synthesis, water photolysis for hydrogen production, photocatalytic ammonia synthesis, and the luminescence and energy transfer of rare earth ions. In 1975, research on the photo-initiated synthesis of **silicone rubber monomers, carried out in collaboration with the Jilin Chemical Industry Research Institute, won the third prize for scientific research from the Ministry of Chemical Industry. In his later years, he devoted great attention to keeping track of international academic developments. He was among the first in China to conduct research on L-B membranes, and in the late 1970s, he guided his doctoral students to explore this field of study, thereby laying the intellectual foundation for his research team. The research work guided and directly participated in by Cai Lisheng achieved excellent results based on his academic ideas, yet he insisted on not having his name listed when papers were published. After 1960, his name appeared in none of the nearly a hundred papers published by his research team, making him an anonymous hero admired by many. Just a few days before his death, while still in bed, he was discussing a research project with several young scholars from the Changchun Institute of Applied Chemistry under the Chinese Academy of Sciences. He took careful notes and expressed his opinions thoughtfully. Cai Lisheng dedicated his entire life to the country’s education and science sectors. In October 1983, Cai Liu passed away from illness in Changchun.

This post was last edited by Desert Fish on 2017-9-14 00:16. During his time working at Yenching University, Cai Lusheng received enthusiastic care and relatively favorable treatment from the Party and the government. In 1952, as part of the restructuring of departments in Chinese universities, the Ministry of Education decided to assign one renowned professor from Peking University, Tsinghua University, and Yenching University to assist Jilin University, with each of them serving as the head of the departments of mathematics, physics, and chemistry respectively. When the education ministry officials urged Cai Liuseng to go to the Northeast, he didn’t hesitate at all and gladly agreed to respond to the Party’s call and go to a difficult area to start a new life there. Before leaving, he and his wife did not take any luxury furniture or famous paintings; instead, they brought with them a small set of equipment such as balances, oil diffusion pumps, light receivers, glass instruments, and valuable chemical reagents, as well as a collection of books and materials. Upon arriving at Jilin University, he worked closely with professors such as Tang Aoqing, Guan Shizhi, and Tao Weisun to establish the Department of Chemistry at Jilin University. He led 7 middle-aged and young teachers as well as 11 recent university graduates from Yenching University, Peking University, Tsinghua University, Jiaotong University, Zhejiang University, Fudan University, Jinling University, and Northeast Normal University in this effort. He first focused on the teaching plan. To implement the teaching plan, he carefully organized the teaching teams for several core courses, ensuring that teachers with high academic standards and extensive teaching experience regularly conducted model lessons. In this way, the Department of Chemistry quickly developed a group of instructors for basic courses, ensuring the quality of teaching. Once teaching operations were back on track, he focused on building a research team, and rapidly developed distinctive research directions in disciplines such as inorganic chemistry, organic chemistry, analytical chemistry, polymer chemistry, and physical chemistry. In the early days of the establishment of the department, conditions in every regard were extremely difficult; under the leadership of Cai Liuseng, all the teachers and students in the department built their own laboratory benches and fabricated experimental instruments. The instruments, equipment, and chemical reagents he brought from abroad all played a vital role. At the same time, he often asked his friends abroad to purchase scarce chemical drugs on his behalf. Through the persistent efforts of Cai Liuseng and these intellectuals in advancing education and research, over the past 30 years, the Department of Chemistry at Jilin University has grown from small beginnings to become a strong institution, with rapid development in both teaching and research activities. To **train nearly 5,000 undergraduates and nearly 400 postgraduate students. A series of **key scientific research tasks were undertaken and completed, and many of these research projects won awards such as the China Science Congress Award, Natural Science Awards, Science and Technology Progress Awards, as well as awards from various ministries, departments, and provincial and municipal authorities. The Department of Chemistry at Jilin University has ranked among the leading institutions in China and holds a certain influence internationally. To meet the needs of development, the Institute of Theoretical Chemistry, the Department of Molecular Biology, and the Department of Environmental Science were established successively from the Department of Chemistry.

　Cai Lisheng has always argued that teachers in higher education institutions must be able to undertake teaching duties as well as conduct scientific research. Only in this way can one improve one’s academic standards and teaching quality, and thus cultivate high-caliber talents. Not long after the department was established, the research team he supervised quickly achieved significant results. To meet the needs of experiments, he also supervised the laboratory technicians and worked personally; as a result, products such as the \"capillary high-pressure mercury lamp,\" \"hydrogen spectrum lamp,\" and \"Geiger counter\" were developed successfully, filling **gaps that existed at that time. Cai Lisheng’s achievements in teaching and research were highly recognized, and in 1957 he was elected as a member of the Chemistry Division of the Chinese Academy of Sciences. Over time, the Department of Chemistry at Jilin University gradually became one of China’s renowned research centers in catalytic kinetics. In 1963, **the task of establishing a research center for catalytic kinetics was assigned to Cai Liuseng. Within two years, the Department of Chemistry established a catalytic kinetics research laboratory with 30 members. Large-scale instruments such as mass spectrometers, spectrometers, and chromatographs were quickly installed and brought into operation, and all the chemistry laboratories were able to start working. The research topic designated by Cai Liuseng for the laboratory is \"Oxidation of methane to formaldehyde\", a topic that holds both significant academic importance and great potential for practical applications. Cai Liuseng reviewed a large amount of literature and, through theoretical analysis, concluded that in the process of methane being oxidized to formaldehyde, an intermediate product called methyl peroxide may be formed, and methyl peroxide further decomposes to produce formaldehyde. Under his guidance, the research laboratory carried out comprehensive studies on the synthesis of methyl peroxide, as well as its photolysis and thermal decomposition. The synthesis process of methyl hydrogen peroxide is highly prone to explosions; despite the risks, Cai Liusheng often participated in the experiments personally. As a result, he came to understand clearly the patterns related to the synthesis, storage, and decomposition of methyl hydrogen peroxide, reaching an international level in this field of study. To understand the microscopic reaction processes and mechanisms, Cai Liuseng not only continued to develop tracer atom technology but also deployed resources to establish modern physical experimental methods such as mass spectrometry analysis, chromatography analysis, and flash photolysis. Among them, the flash photolysis apparatus was already capable of being used to study microsecond-scale chemical processes in 1964, filling a gap in the country. 　　 　　Cai Lisheng was a pioneer in photochemical research in China. In the 1970s, he took on the key research project \"Research on Light and Laser Catalysis\" assigned by the Science and Technology Commission, the Education Commission, and the Jilin Province Science and Technology Commission. Homogeneous photochemistry is a field of research he is familiar with. In 1975, he collaborated with the Jilin Chemical Industry Research Institute to synthesize **alkyl dichlorosilanes using photochemical methods; these silanes could be further used to produce silicone rubber. This type of silicone rubber possesses excellent resistance to high and low temperatures as well as good sealing properties; it is a material that is in urgent need in China’s aerospace industry. Under his guidance, a reaction pathway based on UV-induced free radicals was employed, and through numerous experiments the optimal light source was identified, thereby resolving the problem of detonation. This research achievement successfully passed pilot and pilot-scale tests at the Jilin Chemical Industry Research Institute; both the yield and selectivity of the monomer exceeded the international standards at that time, and the silicon rubber produced met the urgent needs of the aerospace industry. This achievement won the third prize from the Ministry of Chemical Industry in 1981.

In the field of multiphase photocatalysis, Cai Liusheng supervised graduate students in their research on the photocatalytic splitting of water, achieving results of significant academic importance: in addition to the important role of electron excitation, the vibration excitation of water molecules also plays a crucial role in the process of water splitting. Among photocatalysts doped with rare earth elements, those that enable water molecules to acquire vibrational excitation exhibit the highest efficiency in water photolysis. In 1974, he actively guided research on infrared vibration laser chemistry. It took nearly two months to develop a CO2 laser with a power output of 100 W. Through research on the oxidation of ethylene, it was concluded that rapid energy transfer between and within molecules limits the selectivity of vibration-induced reactions; in other words, there is no fundamental difference between the products of reactions triggered by infrared lasers and those of thermal reactions. Unless extremely fast pulsed lasers are used, the selectivity of such reactions may not improve. Due to a series of achievements and academically significant conclusions obtained in the research on light and laser catalysis, the project successfully passed the expert evaluation at its conclusion and received praise from peers. 　　In his later years, Cai Lisheng paid special attention to the developments in the preparation of molecularly ordered systems and the study of their functional properties. He believed that low-temperature matrix isolation systems, LB films, and other ordered molecular membranes were all strategically important areas worthy of research; in 1979, he supervised a graduate student in the study of LB films. After his death, his research team continued to conduct in-depth studies based on his academic ideas. This group has made significant progress in the design and preparation of low-dimensional conductive films as well as their structural characterization, in the study of interlayer chemical reactions in LB films, in the investigation of molecular orientation and arrangement, and in the exploration of the properties of special phospholipid film systems. A doctoral student who made contributions in this area received the Chinese Chemical Society’s 1988 China Young Chemist Award.

Professor Cai’s main contributions throughout his life were in teaching and research on “catalytic decomposition”.

I read that there are many outstanding people at this school