Li Meng-Qing, Ma Yu-Long, Ma Xiao-Xia, Sun Yong-Gang, Song Zhi
State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University Yinchuan 750021 China
RSC Adv. 2018 Mar 19;8(20):10907-10913. doi: 10.1039/c8ra00584b. eCollection 2018 Mar 16.
In this work, a mesoporous silica microsphere (MSM) was selected as a support to prepare a bimetallic supported catalyst (15% W-5% Ni/MSM) by a co-impregnation method that was simple and easy to conduct. We wished to improve the capability of catalytic conversion of biomass into ethylene glycol (EG) and 1,2-propylene glycol (1,2-PG). 15% W-5% Ni/MSM was examined on microcrystalline cellulose (cellulose) and corn stalks in a one-pot catalytic process, and total yields of EG and 1,2-PG reached up to 82.40 wt% and 62.60 wt%, respectively. This remarkable catalytic performance of W-Ni/MSM catalyst could be attributed to the synergistic effect between the active sites of Ni and W and the unique structure of MSM, which was suitable for mass transfer and metal loading. Based on physicochemical characterizations, the metal component was well-distributed on the surface of the MSM, and the metallic Ni, W and WO of the fresh catalyst were converted mainly into NiWO during the catalytic conversion of cellulose. To shed light on the reaction mechanism of the catalyzed hydrogenation of biomass, a possible process involving the formation of H WO homogeneous catalysts, cellulose hydrolysis, C-C cleavage and hydrogenation conversion to 1,2-PG and EG was illustrated. Furthermore, the reusability of W-Ni/MSM catalyst was tested and we explored the cause of decreased diols yields. In summary, this work provides important guidance to rationally design effective catalysts for biomass conversion.
在本工作中，选用介孔二氧化硅微球（MSM）作为载体，通过简单易行的共浸渍法制备了双金属负载型催化剂（15%W-5%Ni/MSM）。我们希望提高生物质催化转化为乙二醇（EG）和1,2-丙二醇（1,2-PG）的能力。在微晶纤维素（纤维素）和玉米秸秆的一锅法催化过程中对15%W-5%Ni/MSM进行了考察，EG和1,2-PG的总产率分别达到了82.40 wt%和62.60 wt%。W-Ni/MSM催化剂的这种卓越催化性能可归因于Ni和W活性位点之间的协同效应以及MSM的独特结构，该结构适合传质和金属负载。基于物理化学表征，金属组分在MSM表面分布良好，新鲜催化剂中的金属Ni、W和WO在纤维素催化转化过程中主要转化为NiWO。为了阐明生物质催化加氢的反应机理，阐述了一个可能的过程，包括形成H WO均相催化剂、纤维素水解、C-C键断裂以及加氢转化为1,2-PG和EG。此外，测试了W-Ni/MSM催化剂的可重复使用性，并探究了二醇产率降低的原因。总之，这项工作为合理设计用于生物质转化的有效催化剂提供了重要指导。
