不同结构水钠锰矿催化氧化对苯二酚腐殖化程度的差异及其原因分析

Catalytic Oxidation Difference of Birnessite with Various Structures for the Degree of Humification of Hydroquinone and the Analysis of Reasons

本文合成了一系列不同氧化度的酸性和碱性水钠锰矿,以对苯二酚作为腐殖质形成的前驱物,分析水钠锰矿矿物类型和亚结构变化对对苯二酚腐殖化程度的影响。取得的主要结果有:水钠锰矿的矿物类型和亚结构(锰氧化度、八面体空位、H+、Mn4+和Mn3+含量)对对苯二酚的腐殖化程度具有重要的影响,且矿物类型的影响大于同种矿物不同亚结构产生的影响。酸性水钠锰矿比碱性水钠锰矿含有更多的H+,导致酸性水钠锰矿比碱性水钠锰矿具有更高的氧化容量,反应达到平衡后,对苯二酚腐殖化程度更高。因此,水钠锰矿物中H+含量对对苯二酚腐殖化程度的影响要大于矿物中Mn4+和Mn3+含量的影响。同种类型水钠锰矿氧化度越高,得电子量将越多,氧化容量越大,反应达到平衡后,对苯二酚腐殖化程度越高。

In this paper,acidic and alkaline birnessites with different AOS were synthesized.The influence of mineral structures and substructures of these synthetical and treated birnessites on the oxidation polymerization of hydroquinone,which were used as precusor of soil humification,were studied in detail.The results in this study were listed as follows: The type and substructures(average Mn oxidation state,vacant site,content of H+,Mn4+ and Mn3+) of the birnessites have important influence on the humification speed and degree of hydroquinone.The type of birnessites have much more influence than the substructures of birnessites on the humification speed and degree of hydroquinone.The acidic birnessite contains more H+ than alkaline birnessite,leading to a higher oxidation capacity of acid birnessite than alkaline birnessite.When the reaction reached equilibrium,the products of acid birnessite reacted with hydroquinone have a higher degree of humification.Therefore,the content of H+ have much more impact on the humification degree of hydroquinone than the content of Mn4+ and Mn3+.When birnessite with the same mineral type have higher AOS,they will abtain more electron,and thus possess stronger oxidation ability.