以電化學方法探討黏土礦物對鄰苯二酚的催化作用

Application of Electrochemical Technique to Study the Catalysis of Catechol with Clay Minerals

10.6730/JAAT.200806_9(3).0001

鄭世堃(Shin-Kun Cheng)；陳鴻基(Horng-Ji Chen)；曾志明(Jyh-Myng Zen)

電化學 ； 黏土礦物 ； 鄰苯二酚 ； Electrochemistry ； Catechol ； Clay minerals

台灣農學會報

9卷3期（2008 / 06 / 01）

185 - 205

繁體中文

鄰苯二酚是土壤中廣泛存在的酚酸類化合物，黏土礦物對其催化聚縮的反應物常被認為是有機質的先趨物，故此有其研究上的重要性。由於以往未有用電化學方法來探討，本試驗研究利用網版印刷碳電極結合循環伏安法來探討黏土礦物對鄰苯二酚的催化作用與其和甘胺酸的聚縮反應。試驗結果指出利用電化學方法來探討黏土礦物對鄰苯二酚的催化和聚縮反應是一種迅速方便的方法，且由結果也得知三種黏土礦物對鄰苯二酚的催化與聚縮反應的大小順序為多鐵蒙特石＞高嶺石＞鈉蒙特石。多鐵蒙特石由於其八面體層中的Fe(上標 2+/3+)具有較大的氧化還原效能，故在鄰苯二酚的催化能力上較其它兩種黏土礦物明顯。此外，以黏粒修飾電極的方式來探討催化和聚縮反應雖會受到黏粒膜層孔隙率所影響，但以不同掃描速率的方式來探討黏土礦物表面的催化效能亦不失為是一種迅速方便的方法。

Catechol is a widespread compound as well as a precursor of organic matter in soils. Reportedly, catechol can be catalyzed and polycondensed by clay minerals to produce humic acid. We report here on the catalysis and polycondensation of catechol and glycine by clay minerals using screenprinted carbon electrodes coupled with cyclic voltammetry. The results indicated that the electroanalytical technique used was a rapid and convenient method in studying catalysis and polycondensation of catechol. The order of catalytic ability was: ferruginous smectite＞kaolinite＞Na-montmorillonite. Ferruginous smectite had larger oxidative and reductive power due to the existence of Fe(superscript 2+/3+) in the octahedral layer, and hence its catalysis for catechol was much more obvious than other clay minerals used. Furthermore, porosity of clay film might affect clay-modified electrodes in studying catalysis and polycondensation of catechol. Overall, cyclic voltammetry at different scan rates could be a rapid and convenient method for catalytic study of clay minerals.