An overview of the catalytic selective hydrogenation technologies of benzene into cyclohexene.- Benzene selective hydrogenation thermodynamics, heterogeneous catalytic kinetics catalysis mechanism and scientific essence.- The first-generation catalyst for selective hydrogenation of benzene to cyclohexene-Ru-M- B/ZrO2(M=Fe, La) amorphous alloys.- The second-generation catalyst for selective hydrogenation of benzene to cyclohexene-Ru-Zn-Na2SiO3-PEG-10000.-...