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为了调控含腈基功能烯烃的催化氢甲酰化反应,设计合成了不同表面酸性的钛氧纳米管和Zr-掺杂钛氧纳米管负载Rh催化剂(Rh/TNTs,Rh/Zr-TNTs).随Zr掺杂量的增加,Zr-掺杂钛氧纳米管的表面酸性提高.用XRD、XPS、FT-IR、TEM和低温N2吸脱附等对所合成的催化剂进行了结构及组成表征.催化剂没有显现出与Rh和Zr相关的XRD衍射峰,Rh在纳米管中高度分散;Zr-掺杂钛氧纳米管的比表面积比纯钛氧纳米管的要高,催化剂的比表面积随着载Rh量的增加而减小,其中Rh0百分率也会降低;FT-IR测试结果表明,催化剂中Rh能对CO进行端基羰基式化学吸附.以2-甲基-3-丁烯腈为底物,评价所合成的催化剂对含腈基功能烯的氢甲酰化的催化性能,催化活性随载Rh量而变化,最佳值为0.13 w;提高催化反应温度虽能增加2-甲基-3-丁烯腈的转化率,但也有利于它的异构化;和Rh/TNTs相比,Rh/Zr-TNTs要求的催化温度稍高,Rh/Zr-TNTs表面更强的B酸性有利于催化反应生成直链产物醛.催化剂Rh/Zr-TNTs中的L酸催化活性中心和表面的B酸协同效应是催化2-甲基-3-丁烯腈生成直链醛的主要因素.
In order to control the catalytic hydroformylation of nitrile-containing functional olefins, the titania-based and Zr-doped titanyl-nanotube loaded Rh catalysts (Rh / TNTs, Rh / Zr-TNTs) with different surface acidity were designed and synthesized. The surface acidity of Zr-doped titanium oxide nanotubes increased with the increase of Zr doping content.The structure and composition of the catalysts were characterized by XRD, XPS, FT-IR, TEM and N2 adsorption and desorption at low temperature. The catalysts showed no XRD diffraction peaks related to Rh and Zr, and Rh was highly dispersed in the nanotubes. The specific surface area of Zr-doped titanium oxide nanotubes was higher than that of pure titanium oxide nanotubes. Rh content decreased, and the percentage of Rh0 also decreased. The results of FT-IR indicated that Rh could catalyze carbonyl group of CO in end-capped catalyst. Using 2-methyl-3-butenenitrile as substrate , The catalytic performance of the synthesized catalyst for hydroformylation of nitrile-containing functional groups was evaluated. The catalytic activity varied with the amount of supported Rh, with the optimum value being 0.13 w. Increasing the catalytic temperature could increase the yield of 2-methyl-3 - butadiene-nitrile conversion, but also conducive to its isomerization; Compared with Rh / TNTs, Rh / Zr-TNTs require slightly higher catalytic temperature, Rh / Zr- The stronger B acid on the surface of TNTs facilitates the catalytic reaction to form linear aldehydes.The synergistic effect of the L acid catalytically active center and the surface B on Rh / Zr-TNTs catalyses the formation of 2-methyl-3-butenenitrile Linear aldehydes the main factor.