Modification And Its Hydrogen Adsorption Uptaking Of Mesoporous Materials

Hydrogen, the simplest and most abundant element in the universe, has the potentialto meet this energy need if numerous hurdles in its effect and safe production, storage,and use in fuel cell vehicles can be overcome. In all hydrogen storage techniques,adsorption storage is considered to be the most promising methods, for it has the fastadsorption and desorption rate and is able to be reversible. The key point is how todesign and synthesis of adsorption storage materials.This paper research use mesoporous materials as the supporter, which has a goodadsorption capacity and large pore surface area, with metals or light metal hydrideloading on it, in which way we can make the physisorption and chemisorption together,so that we can get up-to-standard hydrogen storage materials. First of all, we use in-situhydrothermal synthetic method to prepare series of metal modified Ni-MCM-48、Zn-MCM-48and Zn-MCM-41which the ratio of Si/Zn is100. Results of hydrogenadsorption capacity shows hydrogen storage capacity of MCM-48which ratio ofSi/Ni=31is47.95cm3/g in77K、1atm, Zn-MCM-48can be40.69cm3/g. And then, wechoose Ni-MCM-48, which has the highest capacity in our former research, make apreparation by using CVD technique. After using the single factor investigationconcluded the best conditions to make high capacity hydrogen storage materials, we getthe result that it is easier to create high capacity materials under the following conditions:deposition temperature is550℃, temperature rise rate is5k/min,the mass ratio ofPrecursors and template agent is1:2.5,the carrier gas is to use the mixture ofnitrogen-hydrogen,the system is vacuum before charging the carrier gas and keep thesystem vacuum pressure7.5kPa. The sample we get has a adsorption capacity which is48.91cm3/g at77K、1atm. In the last part, we modify the pore pattern of MCM-41andSBA-15to form an ink-bottle–like pore structure and evaluate its hydrogen storagecapacity. Since MCM-41and SBA-15are mesoporous silica materials compose of two-dimensional hexagonal arrays of channels that typically range from2to9nm indiameter, we get a ink-bottle-like pore structure by dipping metals at the surface of thepore. Hydrogen adsorption results shows that different metal shows different effect onthe capacity, and Ni gives the highest improvement. Besides, results shows thatink-bottle-like pore structure can enhance the hydrogen storage capacity. Adsorptioncapacity of an ink-bottle-like Ni-MCM-41can be39.20cm3/g, Ni-SBA-15can be21.28cm3/g at77K、1atm.The characterization methods used in the experiment are XRD, FT-IR, TEM and N2adsorption-desorption.