▎ 摘　　要

NOVELTY - An activated carbon is prepared by (1) dehulling the dried rice, barley, wheat or oats, obtaining rice or wheat kernel particles covered with a layer of bran on the surface, drying, obtaining puffed rice or wheat kernel granules, freeze-drying, (2) performing pre-carbonization treatment on the puffed rice or wheat kernel particles, obtaining calcined product (A), adding to hydrochloric acid solution to soak to remove excess impurities, washing with deionized water, obtaining carbonized product, (4) activating the mixed aqueous solution of sodium hydroxide, potassium hydroxide and sodium bicarbonate as activator, and immersing the carbonized product in the activator, washing with deionized water, drying, heating, calcining, obtaining preliminary activated carbon, filling the preliminarily activated carbon into a fixed bed reactor, adding excess chlorine gas, and activating at 90-120 degrees C for 1-3 hours until when hydrogen chloride gas cannot be detected in the exhaust gas. USE - Activated carbon for 2-cyanopyridine chlorination. ADVANTAGE - The activated carbon has a high specific surface area, excellent catalytic activity and long-term service life, and can effectively reduce the temperature of the catalytic reaction, and slow down coking process. DETAILED DESCRIPTION - An activated carbon is prepared by (1) dehulling the dried rice, barley, wheat or oats, obtaining rice or wheat kernel particles covered with a layer of bran on the surface, drying rice or wheat kernels until the moisture content is 7% or less, feeding into expander, puffing after increasing temperature and pressure, obtaining puffed rice or wheat kernel granules, freeze-drying, (2) performing pre-carbonization treatment on the puffed rice or wheat kernel particles in microwave at 10-20 kW for 4-8 minutes, (3) carbonizing under the protective atmosphere of nitrogen or argon, heating the pre-carbonized rice or wheat kernel pellets to 700 degrees C for 3 hours to pyrolyze at rate of 2 degrees C/minute, obtaining calcined product (A), adding the prepared calcined product (A) to hydrochloric acid solution to soak to remove excess impurities, washing with deionized water, obtaining carbonized product, (4) activating the mixed aqueous solution of sodium hydroxide, potassium hydroxide and sodium bicarbonate as the activator, and immersing the carbonized product in the activator for 6-18 hours, washing with deionized water, drying, heating to 200-250 degrees C in the air and leaving still for 1-2 hours, heating to 700 degrees C under nitrogen or argon atmosphere for calcination, passing 0.1 g/minute of water vapor per gram of carbonized product, calcining for 1-2 hours, obtaining preliminary activated carbon, filling the preliminarily activated carbon into a fixed bed reactor, adding excess chlorine gas, and activating at 90-120 degrees C for 1-3 hours until when hydrogen chloride gas cannot be detected in the exhaust gas.