(613b) Super Activated Hydrochar for Hydrogen Storage

The world is moving towards clearer energy. Hydrogen (H₂) is a source of high gravimetric energy as well as does not produce any carbon dioxide (CO₂) emission. The storage of H₂ is a big concern in today’s world which require high pressure (around 700 bar), low temperature (around -196 °C), and expensive storage material. As a result, the use of H₂ energy is not so popular throughout the world. Various efforts have been undertaken for storing H₂ both chemically and physically. Physical storage has proven more economically viable, while considering the recovery of H₂. Along with the adsorption parameters (e.g., high microporous surface area, large pore volume, etc.), the adsorption sites and the interaction between adsorption sites with hydrogen are vital for storing large volume of hydrogen.

In the last few years, researchers have reported that the surface area and pore types of materials are the key factors for storing H₂. Recently, it has been observed that the presence of oxygen functional groups also plays an important role in uptake H₂. However, the effect of the quantity and type of oxygen functional groups is missing in the literature. In addition to this gap, as per our knowledge, no work has been done on the stability of storage materials as they are experienced with low temperature and high pressure.

Therefore, the objective of this study was to investigate the influence of surface area, pore type, presence of oxygen functional groups on H₂ uptake. Hydrochar was produced from cellulose at 260 °C. Produced hydrochars were chemically activated by KOH at 3 different temperature (600, 700, and 800 °C). BET analysis was conducted to determine the surface area and pore type of the activated chars. In addition, Boehm titration was directed to calculate the oxygen containing functional groups. Finally, Intelligent Gravimetric Analyzer was used to measure H₂ uptake. Analysis showed that, activated char with rich oxygen containing functional groups can store more H₂ compare to the standard materials such as metal organic frameworks (MOFs), covalent organic frameworks (COFs), etc.