Design of High-Pressure NMR Cell for Real-Time Volume Addition, Liquid-Gas Phase Synthesis of Chlathrate Hydrates


Alvaro Miranda, Yougang Mao, and Yong Ba


This work describes a new method for the synthesis of chlathrate hydrates in a high-pressure NMR tube reaction cell. In the past, methods for synthesizing chlathrate hydrates have been impeded by the slow diffusion of the host gas molecules through the solid hydrate layer, which forms at the liquid-gas phase interface, and the slow diffusion into the host solution. However, we have developed a novel devise to circumvent these two obstacles. The devise is able to form hydrates sequentially in small increments which almost eliminates the slow gas diffusion, and the high pressures attainable increases the solubility of the gas in the solution and thus the diffusion of the gas molecules into the solution. Although the current samples prepared have not been analyzed by NMR, visual evidence indicates the shortened formation time for the chlathrate hydrates.