Xiaoguang Yan (, sometimes written as Xiaoguang Yan or Xiao Guang Yan, – ) was a Chinese petrochemist who researched catalysts used in petroleum processing. He was born in Japan to Chinese parents. When he was young, he moved to the United States to study and work, earning a B.A. in chemistry from Pomona College in 1942 after transferring from Pasadena City College in 1940, and later a Ph.D. from the University of Chicago. He returned to China in 1951 after the establishment of the People's Republic of China. He became one of the pioneers of petrochemical research in the PRC, researching various catalysts for hydrocracking, hydroisomerization, and other petroleum processing techniques. He fell out of favor during the Cultural Revolution and committed suicide in 1968 along with his wife and daughter, but was posthumously rehabilitated in 1972. Biography Early life and US years Xiao Guangyan was born in Tokyo Prefecture, Great Japanese Empire, September 15, 1920. His father was Xiao Quanxuan, a military attache at the Embassy of the Republic of China in Japan , and later served as minister in the Wang Jingwei regime. Xiao Guangyan studied at Shanghai Nanyang Model Middle and Primary School from 1928 to 1937, and in February 1937 moved to the United States. Xiao Guangyan entered the Pasadena City College, completed high school in 1938, and completed the freshman and sophomore courses with honors in 1940; he entered the Chemistry Department of Pomona College in 1940, and graduated as a senior in 1942. In the fall of the same year, he became a graduate student in the Department of Chemistry at the University of Chicago, studying for a Ph.D. under James Franck. During this period, he served as a teaching assistant in organic chemistry, physical chemistry and advanced physical chemistry courses. He received a doctorate in physical chemistry in March 1946. After graduation, Xiao Guangyan was employed as an assistant researcher in the Department of Chemistry at the University of Chicago from January 1946 to August 1946. From September 1946 to October 1950, he was a researcher at the Metallurgical Laboratory of the University of Chicago. During November, he worked in the basic research catalysis group of Mobil. While in US Xiao Guangyan participated in the North American Chinese Student Christian Association and other student club activities. The club gatherings were often held at his home. Through these activities he was exposed to