鹵鹽催化雙氧水分解反應的研究

雙氧水與水競爭溶解及溶合鹵化鉀結晶，同時伴隨氧化還原及催化分解反應的進行而產生氧氣，其過程可簡示為：KX_((s))→_H_2O(KX．H_2O)→K^+_((aq))+X^-_((aq)) KX_((s))→_H_2O_2(KX．H_2O_2)→K^+_((aq))+X^-_((aq))+X_(2(aq))+H_2O_((1))+O_(2(g)) 本研究以排水集氣法或水銀壓力計法測量雙氧水催化分解產生氧氣的體積或壓力的變化並探討雙氧水濃度，觸媒濃度及酸鹼度等對反應速率的影響。實驗結果顯示在pH = 6 下，鹵化鉀催化分解雙氧水的能力為：(i) KI_((s)) ＞＞ KBr_((s)) ＞ KCl_((s)) ；(ii) KI_((aq)) ＞＞ KBr_((aq)) ＞ KCl_((aq))；(iii) KI_((s)) ＞ KI_((aq))； KBr_((s)) ＞ KBr_((aq)) ； KCl_((s)) ＞ KCl_((aq))。在相類似反應條件下(pH = 6)，不同觸媒催化分解雙氧水能力依序為KI_((s)) ＞ CuCl_2．2H_2O_((s)) ＞ MnO_(2(s)) ＞CuCl_((s))。

關鍵字

雙氧水；鹵化鉀；二氧化錳；氯化銅；氯化亞銅；催化分解反應

並列摘要

The redox and decomposition reactions of hydrogen peroxide (H_2O_2) catalyzed by potassium halide crystals (KX_((s))) to produce O_(2(g)) take place concomitantly during the competitive dissolution and solvation of KX_((s)) by H_2O_2 and H_2O, as described by the following scheme: KX_((s))→_H_2O(KX．H_2O)→K^+_((aq))+X^-_((aq)) KX_((s))→_H_2O_2(KX．H_2O_2)→K^+_((aq))+X^-_((aq))+X_(2(aq))+H_2O_((1))+O_(2(g)) The volume and the pressure of 02(g) produced during the reaction was measured by the method of displacing water from a graduated cylinder and the manometric method ,respectively. The experimental results indicate that the reactivity of ~s) toward catalyzing the decomposition of H202(pH--6) can be summarizedas follows: (i) KI_((s)) ＞＞ KBr_((s)) ＞ KCl_((s)); (ii) KI_((aq)) ＞＞ KBr_((aq)) ＞ KCl_((aq)); (iii) KI_((s)) ＞ KI_((aq)); KBr_((s)) ＞ KBr_((aq)); KCl_((s)) ＞ KCl_((aq)). Under similar reaction conditionstpfi(pH~6), the relative reactitity of catalysts follows the order ofKI_((s)) ＞ CuCl_2．2H_2O_((s)) ＞ MnO_(2(s)) ＞CuCl_((s)). Mechanistic interpretation of experimental results is also given.

並列關鍵字

hydrogen peroxide ； potassium halide ； manganese dioxide ； cupric chloride ； cuprous chloride ； decomposition reaction

國際替代計量

鹵鹽催化雙氧水分解反應的研究

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