In Situ High-pressure NMR Observations of Formation of Methane Hydrate in the Mesochannels of SBA-15
NMR研究甲烷水合物在中孔SBA-15内的生成

A home-made high pressure apparatus and a static NMR cell capable of standing high pressure up to 10 MPa were employed to study the formation of methane hydrate in SBA-15 with uniform pore size and ordered hexagonal structure. It is found that, under static condition, the introductive period for methane hydrate formation in the mesochannels of SBA-15 is shorter than that for the formation of bulk methane hydrate, suggesting that SBA-15 can promote the formation of methane hydrate. In situ high-pressure ^1H and ^13C NMR studies show that at certain pressure, even in the presence of excess methane, not all the water molecules confined in the mesochannels of SBA-15 can be completely utilized to form methane hydrate.