圆柱状成形Ru/AC氨合成催化剂制备及性能

Preparation and performance of ruthenium ammonia synthesis catalysts supported on cylinder-shaped activated carbon

将水洗处理的椰壳活性炭研磨至小于0．08mm，加入粘合剂挤压成长度3—10mm、Ф3—5mm的圆柱形，颗粒经120℃烘干、1900℃高温处理和400℃经氧、氮等混合气处理后，作为Ru／AC催化剂载体。其侧压强度从无定形的40N·cm^-1提高到成形后的91N·cm^-1，磨耗率从无定形的5％左右降低到成形后的0．05％。以成形椰壳炭为载体的Ru／AC催化剂的活性与无定形活性炭为载体时相当，具有在低温、低压、低氢氮比和原料气高氨含量下高活性的特点，且具有很好的耐热性。与无定形椰壳炭相比，以成形椰壳炭为载体制备的Ru／AC氨合成催化剂更适合工业氨合成装置使用。

Water-washed coconut-shell activated carbon was ground to diameter of less than 0.08 mm, compressed into cylinders with diameter of 3 - 5 mm and length of 3 - 10 mm, dried at 120℃, thermal- ly-treated at 1 900℃, treated in O2-N2 mixed gas and used as the support for Ru/AC ammonia synthesis catalysts. Compression strength of the activated carbon was enhanced from 40 N·cm^-1 in unshaped form to 91 N·cm^-1, and attrition rate lowered from 5% in unshaped form to 0.05%. Activity of the ruthenium catalysts supported on shaped activated carbon was comparable to those supported on unshaped activated carbon. The Ru/AC catalysts feature higher activity under low temperature, low reaction pressure, low H2/N2 ratio, higher activity under high inlet ammonia concentration and good thermal resistance.