When adding C2H4 to AcOH over a H2SO4-SiO2 catalyst to give AcOEt, the activity of the solid-bed catalyst depended on the surface of the carrier; best results were obtained with SiO2 with a surface area of 120 m2/g. In a stationary process, the space-time-yield curve peaked at .apprx.130 h operating time, then decreased to approx. half this value over the next 300 h, whereas in a nonstationary process, the space-time-yield curve peaked at 100 h and did not decrease during the next 400 h of operation. [on SciFinder (R)]