论文部分内容阅读
考察了过量浸渍液浸渍过程中Ce3+的负载规律与机理及其对CeO2/镁铝尖晶石SOx转移剂性能的影响。结果表明,浸渍过程中镁铝尖晶石载体负载Ce3+是一个动态的过程,CeO2的负载量w(CeO2)取决于载体与浸渍液的性质。Ce3+向载体孔内的扩散与吸附减少了CeO2的堵孔现象,改善了CeO2分散的均匀性,提高了SOx转移剂的硫转移性能。提出了过量浸渍液浸渍过程中Ce3+的负载机理:Ce3+的负载是一个扩散与化学吸附相结合的复杂过程,其中镁铝尖晶石载体孑L表面裸露的“-O-Mg-体相”结构中的O2-充当了吸附活性中心的作用。载体孔表面裸露的“-O-Mg-体相”结构选择性地吸附孔内介质中正电性的Ce3+,致使孔内介质与浸渍液间形成Ce3+浓度梯度,使浸渍液中的Ce3+不断扩散迁入载体孔内并被吸附,导致载体w(CeO2)增加和浸渍液中Ce3+减少。
The effect of Ce3 + loading on the performance of CeO2 / Mg-Al-spinel SOx transfer agent during impregnation was investigated. The results show that Ce3 + loading on the Mg-Al spinel is a dynamic process during the impregnation process. The CeO2 loading depends on the properties of the carrier and impregnation solution. The diffusion and adsorption of Ce3 + into the pores of the carrier reduce the blocking of CeO2, improve the uniformity of the dispersion of CeO2 and improve the sulfur transfer performance of the SOx transfer agent. The mechanism of Ce3 + loading during impregnation with excess impregnation solution is proposed. The loading of Ce3 + is a complex process of diffusion and chemisorption. The “-O-Mg-phase” structure exposed on the surface of Mg-Al spinel carrier O2- in the role of the active center of adsorption. The exposed “-O-Mg-bulk” structure on the pore surface of the support selectively adsorbs the positively-charged Ce3 + in the pore medium, resulting in a Ce3 + concentration gradient between the pore medium and the immersion liquid to continuously diffuse Ce3 + in the immersion liquid Into the pores of the support and adsorbed, resulting in an increase of the carrier w (CeO2) and a decrease of Ce3 + in the impregnating solution.