Activated carbon was tested as metal-free catalyst for hydrochlorination of acetylene in order to circumvent the problem of environment pollution caused by mercury and high cost by noble metals. Oxygen-doped and nitrogen-doped activated carbons were prepared and characterized by XPS

TPD and N

2

physisorption methods. The influences of the surface functional groups on the catalytic performancewere discussed base on these results. Among all the samples tested

a nitrogen-doped sample

AC-n-U500

exhibited the best performance

the acetylene conversion being 92% and vinyl chloride selectivity above 99% at 240℃ and C

2

H

2

hourly space velocity 30 h

-1

. Moreover

the AC-n-U500 catalyst exhibited a stable performance during a 200 h test with a conversion of acetylene higher than 76% at 210℃ at a C

2

H

2

hourly space velocity 50 h

-1

. In contrary

oxygen-doped catalyst had lower catalytic activities. A linear relationship between the amount of pyrrolic-N and quaternary-N species and the catalytic activity was observed

indicating that these nitrogen-doped species might be the active sites and the key in tuning the catalytic performance. It is also found that the introduction of

nitrogen species into the sample could significantly increase the adsorption amount of acetylene. The deactivation of nitrogendoped activated carbon might be caused by the decrease of the accessibility to or the total amount of active sites.