Methane activation on Ga‐modified ZSM‐5 zeolites (Ga/ZSM‐5) was studied by solid‐state NMR spectroscopy. Two types of Ga species, namely highly dispersed oxides and cationic Ga species, were determined by ⁷¹Ga QCPMG NMR. The activation of methane on Ga/ZSM‐5 was explored by using ¹³C and ¹H MAS NMR. Four types of Ga‐CH₃ species along with Ga‐OH groups were observed on Ga/ZSM‐5, evidencing different pathways for heterolytic cleavage of C−H bond of methane. Two‐dimensional (2D) ¹H‐¹H correlation NMR experiments provide detailed information on the location and local environment of the Ga‐CH₃ species by correlating the protons in Ga‐CH₃ with those in Ga‐OH and other hydroxyls on zeolite. The structures of different Ga‐CH₃ species were further determined by 2D ¹H‐¹³C heteronuclear correlation NMR experiments, which were supported by theoretical calculations. The activation routes of C−H bond in methane were proposed on Ga/ZSM‐5 zeolite.

中文翻译：

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固态NMR光谱显示Ga修饰的ZSM-5沸石上的多种甲烷活化途径

通过固态NMR光谱研究了Ga修饰的ZSM-5沸石（Ga / ZSM-5）上的甲烷活化。通过⁷¹ Ga QCPMG NMR确定了两种类型的Ga物种，即高度分散的氧化物和阳离子Ga物种。使用¹³ C和¹ H MAS NMR探索了Ga / ZSM-5上甲烷的活化。在Ga / ZSM-5上观察到四种类型的Ga-CH ₃物种以及Ga-OH基团，证明了甲烷CH键的杂合裂解的不同途径。二维（2D）¹ H- ¹ H相关性NMR实验通过关联Ga-CH _3中的质子提供了有关Ga-CH ₃物种的位置和局部环境的详细信息以及Ga-OH中的那些和沸石上的其他羟基。通过2D ¹ H- ¹³ C异核相关NMR实验进一步确定了不同Ga-CH ₃物种的结构，这得到了理论计算的支持。提出了在Ga / ZSM-5沸石上甲烷中CH键的活化途径。