發(fā)布時間：2019-02-17 18:18

【摘要】：以1,2-二苯乙烷為模型分子,考察了N-羥基鄰苯二甲酰亞胺(NHPI)對分子氧氧化斷裂木質(zhì)素分子中C—C鍵的催化作用,比較了Cu、Co和Mn的多種可溶性鹽對NHPI催化活性的促進(jìn)作用,探究了工藝條件對1,2-二苯乙烷氧化的影響規(guī)律。結(jié)果表明:NHPI能夠在溫和條件下催化分子氧氧化1,2-二苯乙烷中的C—C鍵斷裂生成苯甲醛和苯甲酸。可溶性的Cu、Co和Mn鹽都具有助催化作用,其中乙酸錳的助催化作用最強(qiáng)。確定了二苯基乙酮為氧化的初級反應(yīng)產(chǎn)物。發(fā)現(xiàn)提高反應(yīng)溫度、增加乙酸錳用量以及延長反應(yīng)時間,有利于C—C鍵的氧化斷裂和提高小分子產(chǎn)物的選擇性。優(yōu)化的反應(yīng)條件為NHPI為底物物質(zhì)的量的10%,乙酸錳和NHPI之比為1:10,反應(yīng)溫度90℃,氧氣分壓1.0 MPa,反應(yīng)時間8 h,C—C鍵的氧化斷裂產(chǎn)物苯甲醛和苯甲酸的總選擇性可達(dá)76.5%。
[Abstract]:The catalytic effects of N-hydroxyphthalimide (NHPI) on C-C bond in oxygen oxidized lignin molecules were investigated by using 1-diphenylethane as model molecule, and Cu, was compared. Various soluble salts of Co and Mn promoted the catalytic activity of NHPI. The results show that NHPI can catalyze the oxidation of 1 ~ (2 +) -diphenyl ethane to benzaldehyde and benzoic acid under mild conditions. Soluble Cu,Co and Mn salts both had catalytic effects, among which manganese acetate had the strongest catalytic activity. Diphenyl ethyl ketone was determined as the primary product of oxidation. It was found that increasing the reaction temperature, increasing the amount of manganese acetate and prolonging the reaction time were beneficial to the oxidation fracture of C-C bond and the selectivity of small molecular products. The optimum reaction conditions were as follows: 10% of NHPI as substrate, the ratio of manganese acetate to NHPI was 1: 10, the reaction temperature was 90 鈩，

本文編號：2425452