Au负载SBA-15分子筛上葡萄糖氧化反应  

Glucose Oxidation on Au-supported SBA-15 Molecular Sieve

作　　者：叶晓栋 齐国栋[1] 徐君[1,2] 邓风[1] YE Xiaodong;QI Guodong;XU Jun;DENG Feng(National Centre for Magnetic Resonance in Wuhan,State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,Key Laboratory of Magnetic Resonance in Biological Systems,Wuhan Institute of Physics and Mathematics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430071,China;Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院精密测量科学与技术创新研究院,中国科学院武汉物理与数学研究所,中国科学院生物磁共振分析重点实验室,波谱与原子分子物理国家重点实验室,武汉磁共振中心,武汉430071 [2]华中科技大学,武汉国家光电研究中心,武汉430074 [3]中国科学院大学,北京100049

出　　处：《高等学校化学学报》2020年第5期960-966,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21872170,U1932218,21733013)资助.

摘　　要：探讨了金与铝改性的SBA-15分子筛催化剂(Au-Al/SBA-15)上活性中心与葡萄糖氧化制葡萄酸反应性能的关系.通过固体核磁共振波谱(ssNMR)、X射线光电子能谱(XPS)、紫外-可见光谱(UV-Vis)和透射电子显微镜(TEM)等手段对不同Au及Al含量的Au-Al/SBA-15催化剂进行了结构表征.发现Al改性能够在SBA-15载体上产生四配位Al物种,Au主要以单质的形式存在;SBA-15上的四配位Al物种具有稳定Au颗粒大小的作用.通过对比发现,催化剂上的Au和骨架四配位Al物种间的相互协作促进了对葡萄糖氧化的活性,而非骨架Al物种会导致副反应的发生,降低葡萄糖酸产物的选择性.通过固体13CNMR揭示了反应体系中的NaOH能够将强吸附的产物葡萄糖酸分子从催化剂表面解离,保持活性位不被覆盖进而促进反应持续进行.Conversion of glucose to high-valued chemicals is one of the important routes for biomass utilization.Gold and aluminum modified SBA-15 molecular sieve catalysts(Au-Al/SBA-15)were prepared for aerobic oxidation of glucose.The active site-catalytic performance relationship was investigated.The structures of Au-Al/SBA-15 catalysts with different Au and Al contents were characterized by means of solid-state nuclear magnetic resonance(NMR)in combination with other techniques.It was found that four-coordinated Al is generated on SAB-15 and Au mainly exists in form of metallic state.The supported Au can be stabilized by four-coordinated Al,resulting in smaller Au particles on SBA-15.The interaction between Au and Al species promotes glucose oxidation,while the extra-framework Al species causes the side reaction and lower selectivity to gluconic acid.The role of NaOH in the reaction was revealed by 13 C solid-state NMR experiments,it benefits desorption of gluconic acid molecules from the catalyst surface,keeping the active sites uncovered and promoting the reaction.

关 键 词：生物质 葡萄糖氧化 分子筛催化剂 固体核磁共振 构效关系 

分 类 号：O643[理学—物理化学]