Zn、Ce共掺杂对钴基吸附剂脱硫性能的影响

Effect of Zinc and Cerium Codoping on Desulfurization Performance of Cobalt-based Adsorbents for Hydrogen Sulfide

采用共沉淀法制备一系列钴基脱硫剂,考察了Zn和Ce掺杂对其脱硫性能的影响。脱硫性能测试结果显示,只有在Zn和Ce共掺杂的条件下,钴基吸附剂(15%Zn O-15%Ce O2-70%Co3O4)脱硫性能显著提高。在25℃、体积空速3 000 h-1、H_2S质量浓度1.39×10-3g/L的条件下,其穿透硫容为7.44%,是纯Co3O4的3.35倍。在不同温度下测试其脱硫性能,发现在50~150℃内提升速度最快,再升高温度,脱硫性能提升缓慢。通过X射线衍射(XRD)、N2物理吸附、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)对吸附剂进行了表征,结果显示,Zn和Ce共掺杂后,吸附剂的结晶度降低,比表面积增大,孔道结构丰富,Zn^(2+)和Ce^(4+)分别取代Co^(2+)和Co^(3+),所形成的氧空位和表面化学结构的改变有利于提高钴基吸附剂的脱硫性能。

A series of cobalt-based adsorbents were synthesized by co-precipitation method,and the effects of zinc and cerium doping on the desulfurization performance of cobalt-based adsorbents for hydrogen sulfide were investigated. The results showed that the desulfurization performance of zinc and cerium codoped adsorbent（ Zn-Ce-Co） exhibited an obvious improvement. The breakthrough sulfur capacity of Zn-Ce-Co reached 7. 44%,which was 3. 35 times of that of pure Co_3O_4 under the conditions of 25 ℃,GHSV of 3 000 h-1and H_2S concentration of 1. 39 × 10-3g/L. The desulfurization performance of Zn-Ce-Co was studied at different temperatures. It was found that the breakthrough sulfur capacity increased sharply in the range of 50 ℃ to 150 ℃,then increased slowly when the temperature further raised. Subsequently,the adsorbents were characterized by X-ray diffraction（ XRD）,N2 adsorption,scanning electron microscope（ SEM） and X-ray photoelectron spectroscopy（ XPS）. The results indicated that zinc and cerium codoping could lower the crystallinity,increase the BET specific surface area of cobalt-based adsorbent,and make the pore structure of adsorbent abundant zinc and cerium replaced Co^2＋ and Co^（3＋）,respectively. The forming oxygen vacancy and the change of the surface chemical structure could improve the desulfurization performance of cobalt-based adsorbents.