浸渍法制备2 mm粒径Pt-SDB疏水催化剂的研究——竞争吸附剂的影响

Study on Preparation of 2 mm Pt-SDB Hydrophobic Catalyst by Impregnation—Effect of Competitive Adsorbent

摘要: 以粒径为2 mm的球形聚苯乙烯–二乙烯基苯(SDB)为载体，分别用不同浓度的柠檬酸、马来酸、酒石酸和草酸作为竞争吸附剂，浸渍法制备了Pt-SDB疏水催化剂。为了探究竞争吸附剂所产生的影响，使用透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、催化剂催化交换效率(η)等对催化剂进行综合表征。结果表明，当柠檬酸、马来酸、酒石酸和草酸作为竞争吸附剂时，对柠檬酸、马来酸和酒石酸而言，其最佳的预浸渍浓度为0.1 mol/L，对草酸而言最佳的预浸渍浓度为0.2 mol/L；在实验所用到的竞争吸附剂中，草酸的效果相比其他更好，能够将Pt晶粒平均尺寸从7.45 nm减小到2.14 nm，将零价铂含量从19.37%提高到64.94%，催化剂催化效率从52%提高到89%。

Abstract: Using spherical SDB with a particle size of 2 mm as the carrier, different concentrations of citric ac-id, maleic acid, tartaric acid and oxalic acid were used as competitive adsorbents to prepared Pt-SDB hydrophobic catalysts by the impregnation method. In order to study the influence of com-petitive adsorbents on the Pt-SDB hydrophobic catalyst, TEM, XRD, XPS and catalyst catalytic effi-ciency (characterized by catalytic exchange efficiency η) are used to comprehensively characterize the catalyst. The results show that when citric acid, maleic acid, tartaric acid and oxalic acid are used as competitive adsorbents, for citric acid, maleic acid and tartaric acid, the best pre-impregnation concentration is 0.1 mol/L; for oxalic acid ,the best pre-impregnation concentra-tion is 0.2 mol/L, and the effect of 0.1 mol/L oxalic acid is also good; among the competitive adsor-bents used in the experiment, the effect of oxalic acid is better than others, which can reduce the average Pt crystal grain size from 7.45 nm to 2.14 nm, the zero-valent platinum content was in-creased from 19.37% to 64.94%, and the catalytic efficiency was increased from 52% to 89%.