Dehydration of Xylose to Furfural over MCM-41-Supported Niobium-Oxide Catalysts
Dehydration of Xylose to Furfural over MCM-41-Supported Niobium-Oxide Catalysts
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DOI：
10.1002/cssc.201200881
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发表时间：
2013-04-01
期刊：
影响因子：
8.4
通讯作者：
Maireles-Torres, Pedro
中科院分区：
文献类型：
--
作者：
Garcia-Sancho, Cristina;Sadaba, Irantzu;Maireles-Torres, Pedro
制备了一系列二氧化硅基 MCM-41 负载氧化铌催化剂，通过 XRD、N2 吸附脱附、X 射线光电子能谱、拉曼光谱、吡啶吸附与 FTIR 光谱联用进行表征，并测试了 D-木糖脱水生成糠醛的性能。在所使用的操作条件下，所有材料在木糖脱水成糠醛的过程中都具有活性（不包括MCM-41二氧化硅载体）。木糖转化率随着 Nb2O5 含量的增加而增加。当 Nb2O5 负载量为 16wt% 时，在 170 ℃、反应时间 180 分钟后，转化率达到 74.5%，糠醛收率为 36.5%。此外，木糖转化率和糠醛收率随着反应时间和温度的增加而增加，在190℃和100分钟反应时间后分别达到82.8%和46.2%。值得注意的是，反应介质中氯化钠的存在进一步提高了糠醛收率（170℃下反应180分钟后为59.9%）。此外，通过进行至少三次运行来证明催化剂的再利用，而没有损失催化活性并且不需要中间再生步骤。没有观察到明显的铌浸出，并提出了催化剂结构与活性之间的关系。
A series of silica-based MCM-41-supported niobium-oxide catalysts are prepared, characterized by using XRD, N2 adsorptiondesorption, X-ray photoelectron spectroscopy, Raman spectroscopy, and pyridine adsorption coupled to FTIR spectroscopy, and tested for the dehydration of D-xylose to furfural. Under the operating conditions used all materials are active in the dehydration of xylose to furfural (excluding the MCM-41 silica support). The xylose conversion increases with increasing Nb2O5 content. At a loading of 16wt% Nb2O5, 74.5% conversion and a furfural yield of 36.5% is achieved at 170 degrees C, after 180min reaction time. Moreover, xylose conversion and furfural yield increase with the reaction time and temperature, attaining 82.8 and 46.2%, respectively, at 190 degrees C and after 100min reaction time. Notably, the presence of NaCl in the reaction medium further increases the furfural yield (59.9% at 170 degrees C after 180min reaction time). Moreover, catalyst reutilization is demonstrated by performing at least three runs with no loss of catalytic activity and without the requirement for an intermediate regeneration step. No significant niobium leaching is observed, and a relationship between the structure of the catalyst and the activity is proposed.