- 期刊
以GNP法製備不同摻雜之奈米銅氧化物環境觸媒
Fabrication by GNP Method of Copper Oxide Nanopowders Doped with Various Metals
摘要
揮發性有機化合物（VOCs）具有高度的光化學反應力，在陽光下經由紫外線照射，容易被氧化形成游離基，與大氣反應而形成高濃度的臭氧、空氣污染煙霧和致癌物質，如醛、酮及PANs等，故揮發性有機化合物是一種急需處理的氣態污染物。吸附法是常見的VOCs 污染控制方式，此法在常溫下操作可同時處理多種有機蒸氣，並能有效降低氣態污染物質濃度。本文搭配田口法規劃，以GNP 法製備不同金屬元素摻雜之奈米銅氧化物，探討其對丙酮的吸附以及對雙氧水之催化效果。採田口L27 直交表規畫之參數包含：錳、鐵、鈷、鎳、鋅、銀元素摻雜量，和影響材料吸附VOCs 的環境因素（觸媒用量、觸媒環境溫度、VOCs 停留在觸媒的時間、VOCs 的濃度），共11 項因子。結果顯示，在燃料配比0.8、不同金屬元素摻雜7.5 mol%，其吸附效果大部分大於1mg/g；而在燃料配比0.6、不同金屬元素在不摻雜以及在摻雜15 mol%，其吸附效果大部分小於1mg/g。樣品中吸附丙酮效果較差的3 組，吸附量只有0.1~0.5mg/g 之間，比表面積都在40m2/g 以下。樣品中吸附丙酮效果較佳的3 組，吸附量都有大於1mg/g，比表面積都在50m2/g 以上。比較不同金屬元素摻雜及不同價數奈米銅氧化物對雙氧水的催化能力，燃料配比在0.6以及只摻雜錳、鐵、鎳、銀和不摻雜鈷、鋅的情況下，最高可將濃度25%、25ml 雙氧水催化成氧氣的速率達0.85 L/min；而在同樣條件下，市購二氧化錳催化成氧氣的速率只達0.66L/min。
並列摘要
When exposed to the ultraviolet radiation from the sun, volatile organic compounds (VOCs) with their high photochemical reactivity are very likely to generate via oxidation free radicals which in turn work with atmospheric reaction to release high-density ozone, smog, and carcinogens like aldehyde, ketone, and PANs. VOCs are therefore gaseous pollutants in urgent need of effective treatment. Frequently adopted to control VOCs, adsorption technology is capable of simultaneously treating multiple organic vapors at normal temperatures and effectively reducing the concentrations of air pollutants. The study used GNP supplemented by Taguchi method to fabricate copper oxide nanopowders doped with various metals in order to examine the effects on acetone adsorption and the catalytic oxidation of hydrogen peroxide solution. 11 factors were analyzed, including the parameters stipulated the L27 Taguchi orthogonal arrays (regarding the doped amounts of manganese, iron, cobalt, nickel, zinc, and silver) and environmental factors affecting VOCs adsorption (amount and ambient temperature of the catalysts used, duration of VOCs’ adsorption on the catalysts, and concentrations of VOCs). Results of the study indicate an adsorption effectiveness exceeding 1mg/g in most samples when the air-fuel ratio was set at 0.8 and the doped amount of various metals at 7.5 mol%. However, the adsorption effectiveness dropped below 1mg/g in most samples when the air-fuel ratio was set at 0.6 and the doped amount of various metals at 15 mol%, and the result remained the same with air-fuel ratio at 0.6 in the absence of metal doping. For the least effective three samples, acetone adsorption read 0.1~0.5mg/g and the specific surface area stayed below 40m2/g. The most effective three samples, on the other hand, demonstrated an acetone adsorption greater than 1mg/g and a specific surface area over 50m2/g. Regarding the effects of various metal doping and valences of copper oxide nanopowders onthe catalytic oxidation of hydrogen peroxide solution, the highest rate for 25 ml of hydrogen peroxide solution with a concentration of 25% to achieve oxidation read 0.85L/min when the air-fuel ratio was set at 0.6 and only manganese, iron, nickel, and silver were doped (without cobalt and zinc doping). Under the same condition, commercially available manganese dioxides report an obviously lower oxidation rate of 0.66L/m.