Nuclear magnetic resonance(NMR)spectroscopy is a powerful tool for analyzing molecular structure and composition.However,traditional NMR experiments suffer from long acquisition times,especially in multidimensional NM...Nuclear magnetic resonance(NMR)spectroscopy is a powerful tool for analyzing molecular structure and composition.However,traditional NMR experiments suffer from long acquisition times,especially in multidimensional NMR spectroscopy.This problem,to some extent,limits broader applications of NMR techniques.Various methods have been proposed to accelerate sampling,including non-uniform sampling(NUS),multi-FID acquisition(MFA),Hadamard encoding,Fourier encoding,spatial encoding Ultrafast 2D NMR(UF2DNMR),and so on.The review focuses on rapid sampling methods developed in contemporary China,introducing their fundamental principles and applications while discussing their respective advantages and disadvantages.展开更多
采用水热法合成了Nu88分子筛。考察了不同硅源、铝源和模板剂(SDA)对分子筛合成的影响;采用XRD、BET、SEM、NH3-TPD、Py-IR、29Si MAS NMR、27Al MAS NMR等手段对分子筛进行表征,并考察其在甲苯甲醇烷基化反应中的催化性能。结果表明,...采用水热法合成了Nu88分子筛。考察了不同硅源、铝源和模板剂(SDA)对分子筛合成的影响;采用XRD、BET、SEM、NH3-TPD、Py-IR、29Si MAS NMR、27Al MAS NMR等手段对分子筛进行表征,并考察其在甲苯甲醇烷基化反应中的催化性能。结果表明,碱性硅溶胶为硅源、NaAl O2为铝源时,采用1,6-双(N-甲基吡咯烷己烷)溴盐和1,5-双(N-甲基吡咯烷戊烷)溴盐为模板剂均能合成出Nu88分子筛;该分子筛为纳米晶体,具有良好的热稳定性,酸性较弱;其催化性能与β分子筛相似,推测其属于多维、大孔沸石范畴。展开更多
基金financially supported by the National Natural Science Foundation of China(grant numbers 22174118,12411530077,and 22374124).
文摘Nuclear magnetic resonance(NMR)spectroscopy is a powerful tool for analyzing molecular structure and composition.However,traditional NMR experiments suffer from long acquisition times,especially in multidimensional NMR spectroscopy.This problem,to some extent,limits broader applications of NMR techniques.Various methods have been proposed to accelerate sampling,including non-uniform sampling(NUS),multi-FID acquisition(MFA),Hadamard encoding,Fourier encoding,spatial encoding Ultrafast 2D NMR(UF2DNMR),and so on.The review focuses on rapid sampling methods developed in contemporary China,introducing their fundamental principles and applications while discussing their respective advantages and disadvantages.
文摘采用水热法合成了Nu88分子筛。考察了不同硅源、铝源和模板剂(SDA)对分子筛合成的影响;采用XRD、BET、SEM、NH3-TPD、Py-IR、29Si MAS NMR、27Al MAS NMR等手段对分子筛进行表征,并考察其在甲苯甲醇烷基化反应中的催化性能。结果表明,碱性硅溶胶为硅源、NaAl O2为铝源时,采用1,6-双(N-甲基吡咯烷己烷)溴盐和1,5-双(N-甲基吡咯烷戊烷)溴盐为模板剂均能合成出Nu88分子筛;该分子筛为纳米晶体,具有良好的热稳定性,酸性较弱;其催化性能与β分子筛相似,推测其属于多维、大孔沸石范畴。
